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Can you use cat6 cable for telephone?

Due to the evolution of telephone systems we continually are asked for advice on telephone system cabling. Is my existing cabling suitable? Will i need additional points? Can i use Cat6 cable for telephone?

The simple answer is YES. Cat6 for modern telephone systems is a suitable cable to install. However its not just the telephone systems you should be considering when designing an overall cabling installation. Cat5e, Cat6, and Cat6a are all suitable for modern VoIP systems. However your requirements overall will decide if you need a lower or higher specification

The confusion in cabling requirements sometimes comes about due to how system evolved from the legacy BT systems to today’s modern equivalents

Legacy Phone Systems

Legacy phone systems such as the BT phone line on the wall did not use modern data cabling for its connections.  BT standard cable was specifically used to install all the connections. This cable known as CW1308 would be installed for the BT sockets directly back to a BT connection point. Hence the phone lines were separate for the rest of the communications networks.

The BT points were not to a data transmission standard and therefore couldn’t be used for internet such as PC’s or WiFi. Therefore you would have two separate installations

Digital Systems

Telephone systems then progressed through to a digital version which compared to the legacy systems had a bit more flexibility. To begin with standard data cabling was installed from the communications room to both PC’s and Telephones using separate data cables. Furthermore these cables were terminated onto the same patch panels and onto data modules at the desk. These cables were usually Cat5e and sometimes Cat6 cable.

The incoming BT lines were then installed into a digital phone system. Finally individual cables / lines were taken from the phone system onto additional patch panels with each port designating an extension number. These ports would then be “patched” to an outlet number to get a staff member their designated phone number

The shortfall in this system was you needed to add more cables and panels to increase the phone numbers and also re-patching was constantly required if people moved around the office.

VOIP Systems

VoIP is the standard for the modern telephone system. For the most part all offices now either have this system or will eventually move to it. With a VoIP system individual data cables are installed from the communications cabinet to each desk. Some systems install two cables for user. One would be for the phone and one for the PC. In contrast some systems use one cable per user and plug the PC into the phone and use the same cable.

Subsequently the PCs and Phones the same data switches within the data cabinet. The phone number is allocated to the phone itself. Wherever the phone goes the number goes. Therefore moving people and phone numbers is easy and efficient. Furthermore adding new numbers is via software and quick and almost instant

Cabling for telephone systems

In summary to answer can I use Cat6 cable for telephone, the answer is yes of course. However as described above the modern VoIP system is part of an overall data network within your office. Therefore the decision on the cabling you require will depend on a few factors such as those below

  • Required speeds of network
  • Number of outlets
  • Future expansion allowances
  • Restrictions on installation such as false floors and containment
  • Budget

Data Cabling Options

For the majority of installation Cat6 is recommended as the minimum standard for your overall data cabling installation. However a lot of clients still specify a Cat5e installation to minimise costs. Cat5e and Cat6 are both suitable for 1 gigabit speeds and therefore either choice is suitable in a large proportion of installations

At the same time many network requirements are moving to a minimum of 10 gigabit. Thus cat6 has a slight advantage over cat5e in that Cat6 can transmit 10Gig up to 55m. In contrast Cat5e is not suitable for 10Gig. However for a standardised cabling for 10gigabit Cat6a is the standard for installation.

Telephone systems only require a maximum 1 gigabit for transmission and in many cases only 100mb. Therefore many clients believe that they can install Cat5e/Cat6 to the phones and Cat6a to the PC’s for 10 gigabit connections.

While this is technically true and would work it destroys all the advantages of a structured cabling network. A structured cabling design is to standardise all cabling to its maximum design so that for any change in layout, equipment or technology the cabling is suitable.  Furthermore the additional time taken to install 2 different types of cable negates any savings in material costs

Telephone System Data Cabling Advice

In summary our standard guidance on telephone systems is to look at your overall design as a whole. If you only require a gigabit network overall then install Cat6 cable as standard. If budget is an issue then possibly go for Cat5e.

At the same time is 10gigabit is required within your network then our advice is go for Cat6a throughout. This will give you future flexibility and a standard of wiring

For further articles with regards to Telephone and VOIP cabling please visit our Knowledge Center HERE


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