Archive for the ‘Computers’ Category
Colin Yao asked:
Just like copper cables, NEC (National Electrical Code) requires indoor fiber optic cables be marked with their fire and smoking ratings. NEC requires all indoor fiber cables be marked correctly and installed properly for its intended use.
According to NEC, a building’s inside area is divided into three types of sections: plenums, risers and general purpose areas.
:: What is a Plenum area?
A Plenum area is a building space used for air flow or air distribution system. In most buildings, the area above a drop ceiling or under a raised floor is used as the air return (source of air) for the air conditioning. Those drop ceiling and raised floors are also where fiber cables are often installed. If those cables were burning, they would give off toxic fumes and the fumes would be fed to the rest of the building by the air conditioner. As a result, people could be injured even though they are a long way from the fire.
:: What is a Riser area?
A Riser area is a floor opening, shaft or duct that runs vertically through one or more floors
:: What is General Purpose area?
All other area that is not plenum or riser and on the same floor is a general purpose area.
:: Fiber Optic Cable Fire and Smoking Rating Markings
OFNP Cables:
OFNP stands for Optical Fiber Nonconductive Plenum. OFNP cables have fire-resistance and low smoke production characteristics. They can be installed in ducts, plenums and other spaces used for building airflow. This is the highest fire rating fiber cable and no other cable types can be used as substitutes.
OFCP Cables:
OFCP stands for Optical Fiber Conductive Plenum. OFCP cables have the same fire and smoking rating as OFNP cables but they have a conducting armor or central strength member which is usually steel. OFCP cables must be properly grounded at both ends. As a result, OFCP cables can not be installed in the same cable tray or conduit as power cables.
OFNR Cables:
OFNR stands for Optical Fiber Nonconductive Riser. OFNR cables are used in Riser areas which are building vertical shafts or runs from one floor to another floor. OFNR cables can not be installed in plenum areas since they do not have the required fire and smoking rating as Plenum rated cables. OFNP plenum cables can be used as substitutes for OFNR cables.
OFCR Cables:
OFCR stands for Optical Fiber Conductive Riser. OFCR cables have the same fire rating characteristics as OFNR cables but they have conducting armor or central strength member which is usually steel. OFCR cables should also be properly grounded at both ends. OFCP cables can be used as substitutes for OFCR cables. OFCR cables can not be installed in the same cable trays or conduits as power cables.
OFNG Cables:
OFNG stands for Optical Fiber Nonconductive General-Purpose. They are typically used in horizontal cabling, single floor applications. OFNG cables can not be used in plenums or risers. OFNP and OFNR cables both can be used as substitutes for OFNG cables.
OFCG Cables:
OFCG stands for Optical Fiber Conductive General-Purpose. They have the same fire characteristics as OFNG cables but they have conducting armor or central strength members which is typically steel. OFCG cables should be properly grounded at both ends. They should not be installed in the same cable tray or conduits as power cables.
Just like copper cables, NEC (National Electrical Code) requires indoor fiber optic cables be marked with their fire and smoking ratings. NEC requires all indoor fiber cables be marked correctly and installed properly for its intended use.
According to NEC, a building’s inside area is divided into three types of sections: plenums, risers and general purpose areas.
:: What is a Plenum area?
A Plenum area is a building space used for air flow or air distribution system. In most buildings, the area above a drop ceiling or under a raised floor is used as the air return (source of air) for the air conditioning. Those drop ceiling and raised floors are also where fiber cables are often installed. If those cables were burning, they would give off toxic fumes and the fumes would be fed to the rest of the building by the air conditioner. As a result, people could be injured even though they are a long way from the fire.
:: What is a Riser area?
A Riser area is a floor opening, shaft or duct that runs vertically through one or more floors
:: What is General Purpose area?
All other area that is not plenum or riser and on the same floor is a general purpose area.
:: Fiber Optic Cable Fire and Smoking Rating Markings
OFNP Cables:
OFNP stands for Optical Fiber Nonconductive Plenum. OFNP cables have fire-resistance and low smoke production characteristics. They can be installed in ducts, plenums and other spaces used for building airflow. This is the highest fire rating fiber cable and no other cable types can be used as substitutes.
OFCP Cables:
OFCP stands for Optical Fiber Conductive Plenum. OFCP cables have the same fire and smoking rating as OFNP cables but they have a conducting armor or central strength member which is usually steel. OFCP cables must be properly grounded at both ends. As a result, OFCP cables can not be installed in the same cable tray or conduit as power cables.
OFNR Cables:
OFNR stands for Optical Fiber Nonconductive Riser. OFNR cables are used in Riser areas which are building vertical shafts or runs from one floor to another floor. OFNR cables can not be installed in plenum areas since they do not have the required fire and smoking rating as Plenum rated cables. OFNP plenum cables can be used as substitutes for OFNR cables.
OFCR Cables:
OFCR stands for Optical Fiber Conductive Riser. OFCR cables have the same fire rating characteristics as OFNR cables but they have conducting armor or central strength member which is usually steel. OFCR cables should also be properly grounded at both ends. OFCP cables can be used as substitutes for OFCR cables. OFCR cables can not be installed in the same cable trays or conduits as power cables.
OFNG Cables:
OFNG stands for Optical Fiber Nonconductive General-Purpose. They are typically used in horizontal cabling, single floor applications. OFNG cables can not be used in plenums or risers. OFNP and OFNR cables both can be used as substitutes for OFNG cables.
OFCG Cables:
OFCG stands for Optical Fiber Conductive General-Purpose. They have the same fire characteristics as OFNG cables but they have conducting armor or central strength members which is typically steel. OFCG cables should be properly grounded at both ends. They should not be installed in the same cable tray or conduits as power cables.
Colin Yao asked:
Understanding The Basic Terms
1. Dead end pole: Dead end pole is a utility pole on which self-supporting figure 8 aerial cable or a steel messenger is tensioned and terminated into a dead-end fixture.
2. Messenger span: Messenger span refers to the length of continuous steel messenger tensioned between two dead-end poles.
3. Intermediate poles: Intermediate poles are all the poles between two dead-end poles.
Planning
1. Careful planning and preparation are necessary before any aerial cable installations. During the cable route survey, representatives from all necessary parties including utilities, street depart, etc should be present. Before even detailed planning begins, approval should be get from all involved parties. Sufficient clearance for new cable along the right of way should be confirmed during the route survey.
2. Existing poles should be used whenever possible in order to save cost.
3. Where on a pole to place the aerial fiber optic cable? Fiber optic cables weigh less than equivalent copper cables and also sag less, so fiber optic cables should occupy the uppermost available communications space on a pole.
4. Sufficient clearances must be maintained between fiber optic cables and electrical power cables on joint-use poles. You need to refer to current National Electrical Safety Code for the proper clearances.
5. Existing dead-end pole must be evaluated to see whether they can withstand the stresses during aerial cable installation. You have to evaluate whether temporary guying is needed in order to relieve the temporary unbalanced loading during cable installation.
6. Splice locations. Splice locations are usually selected during the cable route survey. They are chosen to allow for the longest possible continuous cable spans and a minimum number of splices. They should be easily accessible to a splicing vehicle.
7. Aerial installation should never be done in wet conditions. And make sure all personnel are properly trained for pole line work.
8. Fiber optic cables (including all dielectric cables) should be properly grounded when installed in the vicinity of high-voltage power cables.
Installation:
Fiber optic cable aerial installation can be done in two ways
1. Lashing a fiber optic cable to a steel messenger
A steel messenger is first installed between the poles. Then a cable reel trailer and truck are used to pull the cable along the messenger. A cable guide and cable lasher are used to wrap around both the messenger and the fiber cable to secure the fiber cable to the messenger. Following the cable lasher is an aerial bucket truck which makes necessary adjustments.
At each pole, the fiber optic cable forms an expansion loop to allow for expansion of the messenger. The expansion loop’s sizes have both a length and a depth, its length should be larger than twice its depth. The fiber cable should also maintain its minimum bending radius at all times.
2. Direct installation of self-supporting figure 8 aerial fiber optic cables
Self-supporting (Figure-8) optical fiber cables greatly simplifies the task of placing fiber optic cables onto a aerial plant. The self-supporting figure-8 cable incorporates both a steel messenger and the fiber cable into a single jacket of Figure-8 cross section.
The combination of strand and optical fiber into a single cable allows rapid one-step installation and results in a more durable aerial plant.
Understanding The Basic Terms
1. Dead end pole: Dead end pole is a utility pole on which self-supporting figure 8 aerial cable or a steel messenger is tensioned and terminated into a dead-end fixture.
2. Messenger span: Messenger span refers to the length of continuous steel messenger tensioned between two dead-end poles.
3. Intermediate poles: Intermediate poles are all the poles between two dead-end poles.
Planning
1. Careful planning and preparation are necessary before any aerial cable installations. During the cable route survey, representatives from all necessary parties including utilities, street depart, etc should be present. Before even detailed planning begins, approval should be get from all involved parties. Sufficient clearance for new cable along the right of way should be confirmed during the route survey.
2. Existing poles should be used whenever possible in order to save cost.
3. Where on a pole to place the aerial fiber optic cable? Fiber optic cables weigh less than equivalent copper cables and also sag less, so fiber optic cables should occupy the uppermost available communications space on a pole.
4. Sufficient clearances must be maintained between fiber optic cables and electrical power cables on joint-use poles. You need to refer to current National Electrical Safety Code for the proper clearances.
5. Existing dead-end pole must be evaluated to see whether they can withstand the stresses during aerial cable installation. You have to evaluate whether temporary guying is needed in order to relieve the temporary unbalanced loading during cable installation.
6. Splice locations. Splice locations are usually selected during the cable route survey. They are chosen to allow for the longest possible continuous cable spans and a minimum number of splices. They should be easily accessible to a splicing vehicle.
7. Aerial installation should never be done in wet conditions. And make sure all personnel are properly trained for pole line work.
8. Fiber optic cables (including all dielectric cables) should be properly grounded when installed in the vicinity of high-voltage power cables.
Installation:
Fiber optic cable aerial installation can be done in two ways
1. Lashing a fiber optic cable to a steel messenger
A steel messenger is first installed between the poles. Then a cable reel trailer and truck are used to pull the cable along the messenger. A cable guide and cable lasher are used to wrap around both the messenger and the fiber cable to secure the fiber cable to the messenger. Following the cable lasher is an aerial bucket truck which makes necessary adjustments.
At each pole, the fiber optic cable forms an expansion loop to allow for expansion of the messenger. The expansion loop’s sizes have both a length and a depth, its length should be larger than twice its depth. The fiber cable should also maintain its minimum bending radius at all times.
2. Direct installation of self-supporting figure 8 aerial fiber optic cables
Self-supporting (Figure-8) optical fiber cables greatly simplifies the task of placing fiber optic cables onto a aerial plant. The self-supporting figure-8 cable incorporates both a steel messenger and the fiber cable into a single jacket of Figure-8 cross section.
The combination of strand and optical fiber into a single cable allows rapid one-step installation and results in a more durable aerial plant.
Colin Yao asked:
The two most common outdoor fiber optic cable installations are pole line aerial installation and underground cable installation. Underground cable installation can be buried directly underground or placed into a buried duct.
Direct burial installation:
Direct burial installations are most common for long cross-country installations. The cables are plowed in or buried in a trench; the installation process can be very quick. The most common cables used for direct burial are steel armored outdoor fiber cables.
Underground duct installation:
Fiber optic cables can also be pulled through underground ducts, which protect the cables from harsh environment. Underground duct installation also provides opportunity for future expansion without the need to dig. This is the most common practice in urban areas. Another benefit is that fiber cables without armor can be used which makes the installation even easier.
Preparation before underground cable installation:
1. Obtain proper right-of-way permits
2. Identify existing underground utilities such as buried cables, pipes
3. Investigate the soil condition in order to determine the installation depth, whether duct should be used, the type of fiber cable should be used and plowing equipment needed
Cable Burial techniques:
1. Plowed under
Plowing in a fiber cable is faster than trenched. But this process has to be carefully monitored to prevent from damaging the cable.
2. Trenched
The fiber cable can also be trenched. This process is slower than plowing in; however, it allows a much more controlled cable installation. Trenches can be dug by hand or by machine.
3. Directional boring
Directional boring technique is used where the surface cannot be worked on such as high, railway crossings, etc. Instead, a boring machine is used to bore a several inches diameter hole underneath the surface, a duct is pulling through the hole and then fiber cables pulled into the duct.
Important factors:
1. Cable installation depth: up to 40 inches
The depth that fiber cables should be buried is determined by the soil conditions and surface usage. In colder areas, fiber cables are typically buried below the frost line to prevent the cables from being damaged by ground frost heaves.
2. Keep the trenches as straight as possible
Fiber cable trenches should be straight, and the trench bottom should be flat and level. Backfill can also be used to distribute the cable load evenly and protect the cables.
3. Fiber cable warning labels should be buried directly above the cable
Fiber optic warning cables are typically buried directly above the cables to warn future digging operations. Or concrete slabs can be buried below the warning label but above the cables to provide even more protection.
4. Whenever conducting armored fiber cables are used, they should be properly grounded
In direct burial installations, steel armored fiber cables are often chosen for their strength and protection from rodent bites. A very important thing to keep in mind is to properly ground the cables. They should be grounded at all termination points, splices and building entrances. The cable steel armor should be connected to a ground wire using a compression-type clamp. The cable ground wire is then bolted to a nearby ground terminal strip.
5. Fiber optic cable minimum bending radius should always be observed during installation.
The two most common outdoor fiber optic cable installations are pole line aerial installation and underground cable installation. Underground cable installation can be buried directly underground or placed into a buried duct.
Direct burial installation:
Direct burial installations are most common for long cross-country installations. The cables are plowed in or buried in a trench; the installation process can be very quick. The most common cables used for direct burial are steel armored outdoor fiber cables.
Underground duct installation:
Fiber optic cables can also be pulled through underground ducts, which protect the cables from harsh environment. Underground duct installation also provides opportunity for future expansion without the need to dig. This is the most common practice in urban areas. Another benefit is that fiber cables without armor can be used which makes the installation even easier.
Preparation before underground cable installation:
1. Obtain proper right-of-way permits
2. Identify existing underground utilities such as buried cables, pipes
3. Investigate the soil condition in order to determine the installation depth, whether duct should be used, the type of fiber cable should be used and plowing equipment needed
Cable Burial techniques:
1. Plowed under
Plowing in a fiber cable is faster than trenched. But this process has to be carefully monitored to prevent from damaging the cable.
2. Trenched
The fiber cable can also be trenched. This process is slower than plowing in; however, it allows a much more controlled cable installation. Trenches can be dug by hand or by machine.
3. Directional boring
Directional boring technique is used where the surface cannot be worked on such as high, railway crossings, etc. Instead, a boring machine is used to bore a several inches diameter hole underneath the surface, a duct is pulling through the hole and then fiber cables pulled into the duct.
Important factors:
1. Cable installation depth: up to 40 inches
The depth that fiber cables should be buried is determined by the soil conditions and surface usage. In colder areas, fiber cables are typically buried below the frost line to prevent the cables from being damaged by ground frost heaves.
2. Keep the trenches as straight as possible
Fiber cable trenches should be straight, and the trench bottom should be flat and level. Backfill can also be used to distribute the cable load evenly and protect the cables.
3. Fiber cable warning labels should be buried directly above the cable
Fiber optic warning cables are typically buried directly above the cables to warn future digging operations. Or concrete slabs can be buried below the warning label but above the cables to provide even more protection.
4. Whenever conducting armored fiber cables are used, they should be properly grounded
In direct burial installations, steel armored fiber cables are often chosen for their strength and protection from rodent bites. A very important thing to keep in mind is to properly ground the cables. They should be grounded at all termination points, splices and building entrances. The cable steel armor should be connected to a ground wire using a compression-type clamp. The cable ground wire is then bolted to a nearby ground terminal strip.
5. Fiber optic cable minimum bending radius should always be observed during installation.
Colin Yao asked:
:: 1. What is the difference between copper cable and fiber optic cable?
Even though fiber optic cables may look like traditional copper cables, we should always keep in mind that inside fiber cables are fragile glass fibers which can be broken easily if not properly handled.
:: 2. What are the most important things to obey in fiber cable installation?
During any fiber optic cable installation project, we must keep two very important things in mind: First, never over-bend the fiber cable over its minimum bend radius. Second, never pull over the cable manufacturer’s cable pulling tension specification.
:: 3. What is a Minimum Bend Radius?
Fiber cables all have a minimum bend radius specification by the manufacturers. This the minimum curve radius while bending the fiber cable in either installation process or after the installation in its final resting position. You can make larger curves but never smaller than specified.
:: 4. What is Fiber Cable Loaded Minimum Bend Radius?
Loaded minimum bend radius is the fiber cable bend radius specification during a cable pull as in the installation process. The cable must not bend tighter than its loaded minimum bend radius at any time during the installation process. Loaded minimum bend radius is larger than unloaded minimum bend radius as explained below.
:: 5. What is Fiber Cable Unloaded Minimum Bend Radius?
Unloaded minimum bend radius is the fiber bending radius specification in the cable’s final resting position after installation. That is when the cable is not under any tension. Unloaded minimum bend radius is smaller than loaded minimum bend radius. Often, this spec is determined by a simple multiplication such as 15~25 X OD (fiber cable outside diameter).
:: 6. What is Fiber’s Minimum Bend Radius?
Fiber optic cables are composed of individual fibers (strands). Individual fibers also have a minimum bend radius specification, which is usually 2~3 cm and is much smaller than jacket cables.
:: 7. What will happen if a fiber cable is bent smaller than its minimum bend radius?
Bending a fiber cable over its minimum bend radius is one of biggest factors in fiber damaging in fiber cable installation projects. This practice can either break the inside fibers or increase fiber attenuation (fiber power loss) over the manufacturer’s specification. Even if the inside fibers are already broken, you may not see any physical damage to the outside jacket at all. The consequence is, you have to replace the whole section or even the entire length of cable. As a good practice, all fibers need to be thoroughly tested after cable installation.
:: 8. What is Pulling Tension?
Pulling tension is the force placed on per square unit of fiber cable cross section. Maximum pulling tensions during fiber cable installation are specified by cable manufacturers and should not be exceeded at any time. Most tensile load on a cable will occur in a vertical installation and is caused by the cable’s own weight.
:: 9. Other Fiber Optic Cable Installation Tips
a. The cable should be pulled by hand as much as possible
b. Pulling tension should always be monitored when using mechanical pulling techniques
c. Cable should be pulled in a steady, continuous motion and never jerked
d. Never push a fiber optic cable
e. Using the minimum possible tension while pulling fiber cables
:: 1. What is the difference between copper cable and fiber optic cable?
Even though fiber optic cables may look like traditional copper cables, we should always keep in mind that inside fiber cables are fragile glass fibers which can be broken easily if not properly handled.
:: 2. What are the most important things to obey in fiber cable installation?
During any fiber optic cable installation project, we must keep two very important things in mind: First, never over-bend the fiber cable over its minimum bend radius. Second, never pull over the cable manufacturer’s cable pulling tension specification.
:: 3. What is a Minimum Bend Radius?
Fiber cables all have a minimum bend radius specification by the manufacturers. This the minimum curve radius while bending the fiber cable in either installation process or after the installation in its final resting position. You can make larger curves but never smaller than specified.
:: 4. What is Fiber Cable Loaded Minimum Bend Radius?
Loaded minimum bend radius is the fiber cable bend radius specification during a cable pull as in the installation process. The cable must not bend tighter than its loaded minimum bend radius at any time during the installation process. Loaded minimum bend radius is larger than unloaded minimum bend radius as explained below.
:: 5. What is Fiber Cable Unloaded Minimum Bend Radius?
Unloaded minimum bend radius is the fiber bending radius specification in the cable’s final resting position after installation. That is when the cable is not under any tension. Unloaded minimum bend radius is smaller than loaded minimum bend radius. Often, this spec is determined by a simple multiplication such as 15~25 X OD (fiber cable outside diameter).
:: 6. What is Fiber’s Minimum Bend Radius?
Fiber optic cables are composed of individual fibers (strands). Individual fibers also have a minimum bend radius specification, which is usually 2~3 cm and is much smaller than jacket cables.
:: 7. What will happen if a fiber cable is bent smaller than its minimum bend radius?
Bending a fiber cable over its minimum bend radius is one of biggest factors in fiber damaging in fiber cable installation projects. This practice can either break the inside fibers or increase fiber attenuation (fiber power loss) over the manufacturer’s specification. Even if the inside fibers are already broken, you may not see any physical damage to the outside jacket at all. The consequence is, you have to replace the whole section or even the entire length of cable. As a good practice, all fibers need to be thoroughly tested after cable installation.
:: 8. What is Pulling Tension?
Pulling tension is the force placed on per square unit of fiber cable cross section. Maximum pulling tensions during fiber cable installation are specified by cable manufacturers and should not be exceeded at any time. Most tensile load on a cable will occur in a vertical installation and is caused by the cable’s own weight.
:: 9. Other Fiber Optic Cable Installation Tips
a. The cable should be pulled by hand as much as possible
b. Pulling tension should always be monitored when using mechanical pulling techniques
c. Cable should be pulled in a steady, continuous motion and never jerked
d. Never push a fiber optic cable
e. Using the minimum possible tension while pulling fiber cables
Colin Yao asked:
Fiber optic cables are exposed to electrical, mechanical, chemical and environmental elements, so proper installation is critical for the long-term stability and survival of fiber cables.
Cable installation must also meet the NEC(National Electric Code) and local building codes. NEC indicates that fiber optic cables can be placed in the same raceway, cable tray or enclosure with CATV, telephone, communication circuits and Class 2 and 3 remote control signaling circuits.
Note that you should never put the fiber optic cable in the same enclosure that houses electrical terminations.
What are conduits?
Conduit is a tube or trough for protecting electrical or communication wires and cables. It may be a solid or flexible tube in which cables are run. They house and protect the fiber optic cables as well as any other type of data or communication transmission line.
Underground conduits are also called ducts and consist of one or more conduits spaced closely together. They are often buried directly in the ground in concrete casing. Duct lines terminate in underground vaults called manholes. Conduits are made of fiber, PVC, PE and other materials.
Above ground conduits are made of metal or nonmetal materials. They can be used in exposed or concealed locations aboveground.
Characteristics of a good conduit installation
1. Good mechanical properties to withstand the forces imposed by cable installations
2. Observes fiber optic cables minimum bending radius
3. No sharp edges or bends touches the fiber optic cables throughout the route
4. Meets current and future expansion requirements
What are cable trays?
A cable tray is an assembly of units made of metal or other noncombustible materials that form a continuous, rigid support for fiber cables. Cable trays are used throughout the industry and they greatly simplify the installation of fiber optic cables.
Cable trays come in several different types including ladder type, trough type, channel type and solid-bottom type.
Ladder type cable tray is a metal structure consisting of two longitudinal side rails connected by individual transverse members. The transverse members provide the support for fiber cables.
Trough type cable tray is also a metal structure. It consists of a ventilated bottom and has closely spaced supports within integral or separate longitudinal side rails.
Channel type cable tray consists of a one-piece ventilated or solid-bottom channel section.
Solid-bottom type cable tray is a metal structure that has no openings in the bottom. Integral or separate longitudinal side rails provide the support for the fiber cables.
What are pull boxes?
Pull boxes are used to break up long conduit lengths for easier and lower tension cable pulls.
Pull boxes are usually placed near conduit bends and in long straight runs. You should use at least one pull box after every second 90° bend and in long conduit spans.
When pulling cable out of pull boxes, ensure that the cable’s minimum bend radius is always observed. Cable pulled through a corner pull box should first be pulled into a loop since the sharp corner of the pull box can easily damage the cable and the fibers.
Fiber optic cables are exposed to electrical, mechanical, chemical and environmental elements, so proper installation is critical for the long-term stability and survival of fiber cables.
Cable installation must also meet the NEC(National Electric Code) and local building codes. NEC indicates that fiber optic cables can be placed in the same raceway, cable tray or enclosure with CATV, telephone, communication circuits and Class 2 and 3 remote control signaling circuits.
Note that you should never put the fiber optic cable in the same enclosure that houses electrical terminations.
What are conduits?
Conduit is a tube or trough for protecting electrical or communication wires and cables. It may be a solid or flexible tube in which cables are run. They house and protect the fiber optic cables as well as any other type of data or communication transmission line.
Underground conduits are also called ducts and consist of one or more conduits spaced closely together. They are often buried directly in the ground in concrete casing. Duct lines terminate in underground vaults called manholes. Conduits are made of fiber, PVC, PE and other materials.
Above ground conduits are made of metal or nonmetal materials. They can be used in exposed or concealed locations aboveground.
Characteristics of a good conduit installation
1. Good mechanical properties to withstand the forces imposed by cable installations
2. Observes fiber optic cables minimum bending radius
3. No sharp edges or bends touches the fiber optic cables throughout the route
4. Meets current and future expansion requirements
What are cable trays?
A cable tray is an assembly of units made of metal or other noncombustible materials that form a continuous, rigid support for fiber cables. Cable trays are used throughout the industry and they greatly simplify the installation of fiber optic cables.
Cable trays come in several different types including ladder type, trough type, channel type and solid-bottom type.
Ladder type cable tray is a metal structure consisting of two longitudinal side rails connected by individual transverse members. The transverse members provide the support for fiber cables.
Trough type cable tray is also a metal structure. It consists of a ventilated bottom and has closely spaced supports within integral or separate longitudinal side rails.
Channel type cable tray consists of a one-piece ventilated or solid-bottom channel section.
Solid-bottom type cable tray is a metal structure that has no openings in the bottom. Integral or separate longitudinal side rails provide the support for the fiber cables.
What are pull boxes?
Pull boxes are used to break up long conduit lengths for easier and lower tension cable pulls.
Pull boxes are usually placed near conduit bends and in long straight runs. You should use at least one pull box after every second 90° bend and in long conduit spans.
When pulling cable out of pull boxes, ensure that the cable’s minimum bend radius is always observed. Cable pulled through a corner pull box should first be pulled into a loop since the sharp corner of the pull box can easily damage the cable and the fibers.
Lokesh Kumar asked:
De de telefoondienst heeft van VoIP de telecommunicatiewereld door onweer overgenomen! Dit is goedkoop en heeft heel wat eigenschappen die met PSTN (landlines) vergelijkbaar zijn; het is het beste ding voor individuele gebruikers, kleine ondernemingen en grote ondernemingen. Wordt u vermoeid van het betalen van reusachtige telefoonrekeningen voor interlokale telefoongesprekken en internationale vraag? Bezit wilt u een kleine onderneming en de dienst van de lage kostentelefoon? De de telefoondienst van VoIP is voor U! U kunt met een telefoon draadloos gaan VoIP. Hier zijn 7 stappen die u zullen helpen op VoIP overschakelen gaan wireless1. U zult een bijgewerkte computer nodig hebben. U zult een promotiecomputer moeten hebben die met software VoIP compatibel is. Wanneer u vergelijkt en dienstverleners kiest, besteed meer aandacht om te zien of zij hun programma’s in werking stellen over Vensters, MacOs of werkende systemen Linux. Vooral, als u MAC of Linux gebruikt, don' t veronderstelt dat alle VoIP telefoondienstverleners hebben=zullen= uw behoeften met. Enkele gemeenschappelijke eigenschappen van computers die de capaciteit beïnvloeden om radio te verstrekken VoIP zijn hardware, motherboards, bewerkersnelheden, geheugen (RAM), video en grafische kaarten. Als uw computer verouderd is, VoIP kan de telefoondienst geen functional.2 zijn. U moet Snelle internettoegang zoals DSL hebben of CableHigh de Snelheid Internet is een must voor VoIP de telefoondiensten aan functie. Daar misschien een paar bedrijven die met dial-up verbinding maar de audiokwaliteit werken is niet soms bevredigend en het is wegens het gebrek aan snelle internetdienst. De verbindingen van Snelle internetdiensten verstrekken de nodig bandbreedte en opbrengs grote kwaliteit audio.3. Wenst u telefoondienst van woon of de de bedrijfsVoIP? Enkele verschillen tussen woon en businessplannen omvatten het 3pen telefax ver*sturen en e-mailmogelijkheden, meer over lange afstand op fundamentele en niet onbeperkte plannen, en sommige bedrijven werpen zelfs in zoetigheden zoals vrij geel boek adverterend voor de plannen telefoondienst van de de bedrijfs van VoIP. Opnieuw, zal het creëren van een lijst van wat u in de dienst wilt VoIP u beter helpen bepalen wat uw telecommunicatievereisten are.4. Vergelijk de Dienst ProvidersThere van de Telefoon VoIP zijn vele factoren die uw keus van VoIP telefoondienstverleners – het aantal van interlokale telefoongesprekken, internationale vraag, telefoondienst enz. de de bedrijfs van VoIP beïnvloeden. Nu is het tijd om diverse dienstverleners te vergelijken. VoIP is zo gemeenschappelijk dat de kansen u kunnen een vriend of een verwant zijn hebben die het kunnen reeds gebruiken! Zo, is het woord van mond goede manier om wat te krijgen terugkoppelt. Vergelijken is belangrijk en er zijn meer te kennen details, zodat leest het artikel bij – http://www.ez-voip-phone-service.com/how-to-compare-voip-phone-service-before-buying/After dat VoIP de telefoondiensten vergelijkt, u kan beslissen welk VoIP de dienstbeste uw behoeften aanpast. Koop dit VoIP plan.5. Kies Uw Eigen partij van CodeA van het Gebied van leveranciers VoIP u de optie zal geven om uw eigen landnummer en telefoonaantal te kiezen. Enkel om duidelijk te zijn – u kunt overal leven en nog een landnummer kiezen van een andere plaats! Dit is een grote optie die slechts in de diensten VoIP en niet in PSTN (landline) beschikbaar is. Dit is ook een goed idee voor bedrijfseigenaars die een bepaald gebied van klant willen richten. Zij kunnen het landnummer van dit bepaalde gebied van klanten kiezen. Nu, voor de klanten, zal deze vraag lokale call.6 zijn. Koop een adapter want uw VoIP PhoneThis belangrijk is als u draadloos wilt gaan en don' t- plan bij het zitten dichtbij computer enkel om uw telefoongesprekken te ontvangen of te maken. De meeste VoIP telefoondienstverleners verzenden u vrije adapter. Als u don' t ontvangt een vrije adapter, dan kunt u kopen. Met een adapter, u don' t moet dichtbij de computer zitten. Dit zal u toestaan om uw huishoudentelefoons te gebruiken om calls.7 te nemen. Andere Belangrijke Dingen over telefoon VoIP serviceAs u weten het, hebben de telefoons VoIP zeer gelijkaardige eigenschappen zoals vestiging uw audio-messagerie, bezoekersidentiteitskaart enz., kunt u het vormen. In feite, is er een Internet controlebord dat u kunt gebruiken om deze features.VoIP telefoondienst te vormen bent absoluut een zegen aan de wereld van mededeling. U kunt zeer goedkope interlokale en internationale telefoongesprekken en telefoondienst gebruiks de de bedrijfs van VoIP voor uw klein of grote onderneming maken -.
De de telefoondienst heeft van VoIP de telecommunicatiewereld door onweer overgenomen! Dit is goedkoop en heeft heel wat eigenschappen die met PSTN (landlines) vergelijkbaar zijn; het is het beste ding voor individuele gebruikers, kleine ondernemingen en grote ondernemingen. Wordt u vermoeid van het betalen van reusachtige telefoonrekeningen voor interlokale telefoongesprekken en internationale vraag? Bezit wilt u een kleine onderneming en de dienst van de lage kostentelefoon? De de telefoondienst van VoIP is voor U! U kunt met een telefoon draadloos gaan VoIP. Hier zijn 7 stappen die u zullen helpen op VoIP overschakelen gaan wireless1. U zult een bijgewerkte computer nodig hebben. U zult een promotiecomputer moeten hebben die met software VoIP compatibel is. Wanneer u vergelijkt en dienstverleners kiest, besteed meer aandacht om te zien of zij hun programma’s in werking stellen over Vensters, MacOs of werkende systemen Linux. Vooral, als u MAC of Linux gebruikt, don' t veronderstelt dat alle VoIP telefoondienstverleners hebben=zullen= uw behoeften met. Enkele gemeenschappelijke eigenschappen van computers die de capaciteit beïnvloeden om radio te verstrekken VoIP zijn hardware, motherboards, bewerkersnelheden, geheugen (RAM), video en grafische kaarten. Als uw computer verouderd is, VoIP kan de telefoondienst geen functional.2 zijn. U moet Snelle internettoegang zoals DSL hebben of CableHigh de Snelheid Internet is een must voor VoIP de telefoondiensten aan functie. Daar misschien een paar bedrijven die met dial-up verbinding maar de audiokwaliteit werken is niet soms bevredigend en het is wegens het gebrek aan snelle internetdienst. De verbindingen van Snelle internetdiensten verstrekken de nodig bandbreedte en opbrengs grote kwaliteit audio.3. Wenst u telefoondienst van woon of de de bedrijfsVoIP? Enkele verschillen tussen woon en businessplannen omvatten het 3pen telefax ver*sturen en e-mailmogelijkheden, meer over lange afstand op fundamentele en niet onbeperkte plannen, en sommige bedrijven werpen zelfs in zoetigheden zoals vrij geel boek adverterend voor de plannen telefoondienst van de de bedrijfs van VoIP. Opnieuw, zal het creëren van een lijst van wat u in de dienst wilt VoIP u beter helpen bepalen wat uw telecommunicatievereisten are.4. Vergelijk de Dienst ProvidersThere van de Telefoon VoIP zijn vele factoren die uw keus van VoIP telefoondienstverleners – het aantal van interlokale telefoongesprekken, internationale vraag, telefoondienst enz. de de bedrijfs van VoIP beïnvloeden. Nu is het tijd om diverse dienstverleners te vergelijken. VoIP is zo gemeenschappelijk dat de kansen u kunnen een vriend of een verwant zijn hebben die het kunnen reeds gebruiken! Zo, is het woord van mond goede manier om wat te krijgen terugkoppelt. Vergelijken is belangrijk en er zijn meer te kennen details, zodat leest het artikel bij – http://www.ez-voip-phone-service.com/how-to-compare-voip-phone-service-before-buying/After dat VoIP de telefoondiensten vergelijkt, u kan beslissen welk VoIP de dienstbeste uw behoeften aanpast. Koop dit VoIP plan.5. Kies Uw Eigen partij van CodeA van het Gebied van leveranciers VoIP u de optie zal geven om uw eigen landnummer en telefoonaantal te kiezen. Enkel om duidelijk te zijn – u kunt overal leven en nog een landnummer kiezen van een andere plaats! Dit is een grote optie die slechts in de diensten VoIP en niet in PSTN (landline) beschikbaar is. Dit is ook een goed idee voor bedrijfseigenaars die een bepaald gebied van klant willen richten. Zij kunnen het landnummer van dit bepaalde gebied van klanten kiezen. Nu, voor de klanten, zal deze vraag lokale call.6 zijn. Koop een adapter want uw VoIP PhoneThis belangrijk is als u draadloos wilt gaan en don' t- plan bij het zitten dichtbij computer enkel om uw telefoongesprekken te ontvangen of te maken. De meeste VoIP telefoondienstverleners verzenden u vrije adapter. Als u don' t ontvangt een vrije adapter, dan kunt u kopen. Met een adapter, u don' t moet dichtbij de computer zitten. Dit zal u toestaan om uw huishoudentelefoons te gebruiken om calls.7 te nemen. Andere Belangrijke Dingen over telefoon VoIP serviceAs u weten het, hebben de telefoons VoIP zeer gelijkaardige eigenschappen zoals vestiging uw audio-messagerie, bezoekersidentiteitskaart enz., kunt u het vormen. In feite, is er een Internet controlebord dat u kunt gebruiken om deze features.VoIP telefoondienst te vormen bent absoluut een zegen aan de wereld van mededeling. U kunt zeer goedkope interlokale en internationale telefoongesprekken en telefoondienst gebruiks de de bedrijfs van VoIP voor uw klein of grote onderneming maken -.
Once you’ve decided to use VoIP for your Small Office Home Office, it’s time to get set up. You’re probably keen to get going, find a VoIP provider, and start saving money on phone calls. It’s a good idea, though, to take a little time to consider some of the points on this check list. That way, you can be sure you’ve chosen the VoIP provider that’s best for you, and best for your business.
Who are the best established VoIP providers?
VoIP isn’t new technology, as such, and though broadband telephony is likely to become the way we all make telephone calls, you want to be sure that your provider is reliable and experienced.
What’s your existing broadband infrastructure?
Make sure you know how your existing broadband works. Is it cable (eg Virgin)? If so, you could cancel your cable telephone line entirely without affecting your broadband connection. If it is ADSL (eg BT), however, you can’t cancel your phone line because you’ll lose your broadband, too. You can, though use a VoIP phone line as your second phone line which you could use to make your business calls.
Do you need just one line, or two?
If you work from home, either all the time or part of the time, you may want to separate business from private telephone calls, so a second, cheap VoIP phone line might make more sense, especially if your business is growing or likely to grow.
What features will help?
Will your customers be able to get hold of you whenever they need to? Check that the VoIP provider offers inclusive features such as call-forwarding, three-way calling, ringback, do not disturb, call waiting or voicemail sent to your email address.
Call plans.
Think about what you need in terms of the business calls you make. Do you call mostly UK numbers? Or do you need to call other European countries, or mostly the US? Look at the call plans the VoIP offers. Is there a good choice? Is there one that suits you? Are calls to mobiles included?
What exactly does ‘unlimited’ mean?
Make sure you understand exactly what the VoIP provider is offering. If it says ‘unlimited’, does this mean that the calls really are unlimited to the countries listed in your call plan? Most VoIP providers will have a ‘fair usage’ policy. That is, they will give you have a generous allowance of free minutes, say 2000 (about 33 hours a month). What is the VoIP’s allowance? Is your SOHO likely to use more minutes than that? What will you pay if that happens?
What will you pay if you call countries outside your plan?
Check what you’ll be charged if you call countries outside the call plan you’ve signed up to. VoIP usually offer very competitive rates, but it’s a good idea to check. If you think you may make regular calls to a country outside one call plan, it may be a good idea to see if there’s another call plan that includes that country.
What do its customers say?
Try and find some of the customer feedback about the VoIP provider. Reviews from customers, either satisfied or disgruntled, will often tell you a lot about what you need to know about a company in terms of reliability, customer service, technical support, customer satisfaction etc.
What are the extra costs?
As well as the advertised monthly call plan, make sure you know exactly what else you might have to pay for. The VoIP provider may, for example, charge a set-up or administration fee, a line activation fee, a cancellation fee. There may be charges for equipment, too, though some of it may be free.
Is the VoIP’s website clear?
You don’t want to have to root through a website to discover hidden charges and the small print. A well written, professional, clear website, with all the charges clearly set out, is a sign that the VoIP provider is committed to professional transparency.
What’s the support like?
A phone line is one of the most crucial elements of any SOHO. So it’s a good idea to make sure that the VoIP provider offers technical support and customer service 24/7. Can you always get hold of someone if you need to? Do you have to pay for this?
What add-ons do they offer?
If or when your business starts to grow, can you adapt your VoIP phone system accordingly? Find out whether the VoIP provider offers add-ons such as a second phone line, a fax line, or the ability to make calls from your laptop.
Can you keep your number?
If you’re starting up in business, it may make sense to get a whole new business number. But if customers already use your landline number, you may want to keep that. Check that the VoIP provider offers the option of ‘porting’ your existing number to your new VoIP phone provider.
Can you choose a dialling code?
You may want a VoIP telephone number that’s local to you. Or you may want one that’s local to your customers. Either way, find out what the VoIP offers in terms of choosing dialling codes, and check that the code you want is available.
What about emergencies?
A final important consideration is to think about how your business would cope if your broadband connection went down. If that happens, and your VoIP telephone is temporarily out of action, you need to make sure you have a back-up plan (such as a mobile), particularly in case of critical business calls or even calls to the emergency services.
Once you’ve been through this check list, you should be ready to choose your VoIP provider. It shouldn’t take long to get your VoIP phone line set up, and then you’ll be ready to start saving money by using your broadband to make and receive business calls.
By: Costas Kariolis
Who are the best established VoIP providers?
VoIP isn’t new technology, as such, and though broadband telephony is likely to become the way we all make telephone calls, you want to be sure that your provider is reliable and experienced.
What’s your existing broadband infrastructure?
Make sure you know how your existing broadband works. Is it cable (eg Virgin)? If so, you could cancel your cable telephone line entirely without affecting your broadband connection. If it is ADSL (eg BT), however, you can’t cancel your phone line because you’ll lose your broadband, too. You can, though use a VoIP phone line as your second phone line which you could use to make your business calls.
Do you need just one line, or two?
If you work from home, either all the time or part of the time, you may want to separate business from private telephone calls, so a second, cheap VoIP phone line might make more sense, especially if your business is growing or likely to grow.
What features will help?
Will your customers be able to get hold of you whenever they need to? Check that the VoIP provider offers inclusive features such as call-forwarding, three-way calling, ringback, do not disturb, call waiting or voicemail sent to your email address.
Call plans.
Think about what you need in terms of the business calls you make. Do you call mostly UK numbers? Or do you need to call other European countries, or mostly the US? Look at the call plans the VoIP offers. Is there a good choice? Is there one that suits you? Are calls to mobiles included?
What exactly does ‘unlimited’ mean?
Make sure you understand exactly what the VoIP provider is offering. If it says ‘unlimited’, does this mean that the calls really are unlimited to the countries listed in your call plan? Most VoIP providers will have a ‘fair usage’ policy. That is, they will give you have a generous allowance of free minutes, say 2000 (about 33 hours a month). What is the VoIP’s allowance? Is your SOHO likely to use more minutes than that? What will you pay if that happens?
What will you pay if you call countries outside your plan?
Check what you’ll be charged if you call countries outside the call plan you’ve signed up to. VoIP usually offer very competitive rates, but it’s a good idea to check. If you think you may make regular calls to a country outside one call plan, it may be a good idea to see if there’s another call plan that includes that country.
What do its customers say?
Try and find some of the customer feedback about the VoIP provider. Reviews from customers, either satisfied or disgruntled, will often tell you a lot about what you need to know about a company in terms of reliability, customer service, technical support, customer satisfaction etc.
What are the extra costs?
As well as the advertised monthly call plan, make sure you know exactly what else you might have to pay for. The VoIP provider may, for example, charge a set-up or administration fee, a line activation fee, a cancellation fee. There may be charges for equipment, too, though some of it may be free.
Is the VoIP’s website clear?
You don’t want to have to root through a website to discover hidden charges and the small print. A well written, professional, clear website, with all the charges clearly set out, is a sign that the VoIP provider is committed to professional transparency.
What’s the support like?
A phone line is one of the most crucial elements of any SOHO. So it’s a good idea to make sure that the VoIP provider offers technical support and customer service 24/7. Can you always get hold of someone if you need to? Do you have to pay for this?
What add-ons do they offer?
If or when your business starts to grow, can you adapt your VoIP phone system accordingly? Find out whether the VoIP provider offers add-ons such as a second phone line, a fax line, or the ability to make calls from your laptop.
Can you keep your number?
If you’re starting up in business, it may make sense to get a whole new business number. But if customers already use your landline number, you may want to keep that. Check that the VoIP provider offers the option of ‘porting’ your existing number to your new VoIP phone provider.
Can you choose a dialling code?
You may want a VoIP telephone number that’s local to you. Or you may want one that’s local to your customers. Either way, find out what the VoIP offers in terms of choosing dialling codes, and check that the code you want is available.
What about emergencies?
A final important consideration is to think about how your business would cope if your broadband connection went down. If that happens, and your VoIP telephone is temporarily out of action, you need to make sure you have a back-up plan (such as a mobile), particularly in case of critical business calls or even calls to the emergency services.
Once you’ve been through this check list, you should be ready to choose your VoIP provider. It shouldn’t take long to get your VoIP phone line set up, and then you’ll be ready to start saving money by using your broadband to make and receive business calls.
By: Costas Kariolis
What is Dialup?
Dialup is the slow and annoying connection speed some of us had to experience, and some of us still do. Dialup is when a modem is used to connect to the wall socket via a cable using a 66-45 cable to connect to the internet. You require an internal modem for this connection or an external modem, most PC’s still come with internal modems and some business’s still use dialup connections for when users go home and use VPN to connect to the company’s servers.
What is Fibre Optic?
This has also been known as the speed of light, up to the gigabytes. This Fibre Optic cable has a bundle of glass threads, which have the ability of sending messages modulated onto light wave. Fibre Optic cables have a much greater bandwidth than metal cables. They have less interference, are much thinner and lighter than metal wires. The data is transmitted digitally not analogically. Fibre optic is very expensive to install as well as being fragile.
What is ISDN?
Meaning Integrated Services Digital Network, a standard to send video, voice and data over a digital telephone line. IDSN connection speeds are from 64Kbps. There are two types of ISDN, these are : ‘basic rate interface’ and ‘primary rate interface’. Basic Rate: Has two B channels consisting of 6Kbps and one D channel for transmitting. Primary Rate: Has 23 B channels and a single D channel.
What is ADSL?
Meaning Asymmetric Digital Subscriber Line, this is the most common type of Internet world wide in today’s society. This allows more data to be sent across existing copper telephone lines. ADSL requires a specific modem and now has the capability of wireless as well as Ethernet. ADSL connections are from 1.5Mbps to 9 Mbps when receiving data. When sending data it can connection up to 16Kpbs to 640kbs
Join us at http://deansitsupport.com
Be in touch soon friend.
Wishing you great success
Dean Barnard
By: Dean Barnard
About the Author:
Dialup is the slow and annoying connection speed some of us had to experience, and some of us still do. Dialup is when a modem is used to connect to the wall socket via a cable using a 66-45 cable to connect to the internet. You require an internal modem for this connection or an external modem, most PC’s still come with internal modems and some business’s still use dialup connections for when users go home and use VPN to connect to the company’s servers.
What is Fibre Optic?
This has also been known as the speed of light, up to the gigabytes. This Fibre Optic cable has a bundle of glass threads, which have the ability of sending messages modulated onto light wave. Fibre Optic cables have a much greater bandwidth than metal cables. They have less interference, are much thinner and lighter than metal wires. The data is transmitted digitally not analogically. Fibre optic is very expensive to install as well as being fragile.
What is ISDN?
Meaning Integrated Services Digital Network, a standard to send video, voice and data over a digital telephone line. IDSN connection speeds are from 64Kbps. There are two types of ISDN, these are : ‘basic rate interface’ and ‘primary rate interface’. Basic Rate: Has two B channels consisting of 6Kbps and one D channel for transmitting. Primary Rate: Has 23 B channels and a single D channel.
What is ADSL?
Meaning Asymmetric Digital Subscriber Line, this is the most common type of Internet world wide in today’s society. This allows more data to be sent across existing copper telephone lines. ADSL requires a specific modem and now has the capability of wireless as well as Ethernet. ADSL connections are from 1.5Mbps to 9 Mbps when receiving data. When sending data it can connection up to 16Kpbs to 640kbs
Join us at http://deansitsupport.com
Be in touch soon friend.
Wishing you great success
Dean Barnard
By: Dean Barnard
About the Author:
Join me at Perth Computer Help and I will be in touch soon friend.
It can be very confusing when you begin to search for the best Internet connectivity and bandwidth needed for your business/home. These include DSL, ADSL, and SDSL…they all look very similar but they do have their differences.
Below are some of these differences between an ADSL line and a SDSL line;
Asymmetric Digital Subscriber Line also known as ADSL, has the ability to download at speeds of up to 512kbps and a maximum upload of 256kbps. This basically means that you are transferring data when you download it at 2mbps yet when you are uploading it, the process would be half of that and is only travelling at 1mbps.
ADSL uses the copper telephone wire that is already in place and allows you to be on the Internet and make a phone call using the same exact line.
Now, when you are using a Symmetric Digital Subscriber Line, otherwise known as an SDSL, you will find that you have the ability not only to upload but to download at the same speed of 512kbps. That is 8 times faster than standard ADSL. The reason that SDSL is able to carry data more quickly is due to the circuits for these lines are made from new copper wire. This new wire does not support the more traditional method being able to make a phone call and also using the same line to connect the Internet at the same time. Due to the difference in technology used, when using SDSL you will need to have a router that is designated for this specific line.
SDSL allows for the transfer of data at same speeds but up and down and it is guaranteed. This is a plus for data applications that need constant high-upstream bit rates, such as VOIP (voice over IP). SDSL is generally preferred by business, as the uploading speed is so much faster than ADSL.
ADSL:
This type of line has a relatively low cost; however it is not available in all areas, although the major metro areas are almost at 70% in availability. The ability to upload is also much slower than download and may not be beneficial if you use the Internet heavily or need it for business purposes. Speed suffers as the bandwidth is aggregated at the main office and is subject to oversubscription. The cost of ADSL is varied depending on the carrier for the area and location of the service.
SDSL:
This line on the other hand has a higher cost. Again this is varied according to who the carrier is, where the service is located and what it will be used for. The ability to upload and download is up to 2mbps both ways. Great for businesses that need the extra speed but don’t want the extra cost when compared to a T-1 line.
It is helpful to understand the difference between an ADSL line and a SDSL line as this will help you to choose which route is best for your needs.
By: Derek Rogers
About the Author:
Below are some of these differences between an ADSL line and a SDSL line;
Asymmetric Digital Subscriber Line also known as ADSL, has the ability to download at speeds of up to 512kbps and a maximum upload of 256kbps. This basically means that you are transferring data when you download it at 2mbps yet when you are uploading it, the process would be half of that and is only travelling at 1mbps.
ADSL uses the copper telephone wire that is already in place and allows you to be on the Internet and make a phone call using the same exact line.
Now, when you are using a Symmetric Digital Subscriber Line, otherwise known as an SDSL, you will find that you have the ability not only to upload but to download at the same speed of 512kbps. That is 8 times faster than standard ADSL. The reason that SDSL is able to carry data more quickly is due to the circuits for these lines are made from new copper wire. This new wire does not support the more traditional method being able to make a phone call and also using the same line to connect the Internet at the same time. Due to the difference in technology used, when using SDSL you will need to have a router that is designated for this specific line.
SDSL allows for the transfer of data at same speeds but up and down and it is guaranteed. This is a plus for data applications that need constant high-upstream bit rates, such as VOIP (voice over IP). SDSL is generally preferred by business, as the uploading speed is so much faster than ADSL.
ADSL:
This type of line has a relatively low cost; however it is not available in all areas, although the major metro areas are almost at 70% in availability. The ability to upload is also much slower than download and may not be beneficial if you use the Internet heavily or need it for business purposes. Speed suffers as the bandwidth is aggregated at the main office and is subject to oversubscription. The cost of ADSL is varied depending on the carrier for the area and location of the service.
SDSL:
This line on the other hand has a higher cost. Again this is varied according to who the carrier is, where the service is located and what it will be used for. The ability to upload and download is up to 2mbps both ways. Great for businesses that need the extra speed but don’t want the extra cost when compared to a T-1 line.
It is helpful to understand the difference between an ADSL line and a SDSL line as this will help you to choose which route is best for your needs.
By: Derek Rogers
About the Author:
Derek Rogers is a freelance writer who writes for a number of UK businesses. For Business Internet Services, ADSL Lines and SDSL Lines he recommends Iconnyx.
