Demarc Extension Wiring Specifications
Demarc Extensions, which extend the wiring from the Network Interface to the inside of a building or through a building to where your equipment sits, are a critical portion of the network. Often, the speeds or stability that a customer can get from ACD is significantly affected by the quality of the inside wiring.
The wiring that ACD recommends is the following, based upon information gathered on testing and debugging and the written specifications from vendors. Changing out your internal wiring may not make a difference, if the wiring you have is of good quality. However, if the wiring is of low quality, then changing out your wiring will make a substantial difference.
Recommendations for DSL or EFM Service Wiring
- Use Solid Core Wire', do not use stranded wire. Stranded wire is what is in cheap phone lines.
- For DSL or EFM copper loops use Cat 5, Cat5E, or Cat 6 wiring from your network interface to your Modem Jack. Basically, the larger the gauge of wire, the better your connection is likely to be. Short lengths of this type of cable can be bought at most home improvement stores.
- Keystone type jacks are the best. These can be purchased at Home Depot, Menards or Lowes in the Electric department. Leviton is the common brand. For cheaper prices you can order this stuff from the web. These stores are usually expensive.
- For Regular DSL Cat 3 RJ-11 Keystone Jacks work fine.
- Ground your power outlets. The power outlets that you have should be grounded in your house, this decreases electromagnetic interference on all wiring in your house.
- Shielded Wiring: For best results, use shielded wire, and ground one end of the shield on a ground.
- Avoid Running Data Lines near Power Lines. Avoiding perpendicular wiring crossing major power lines may significantly improve reliability. For example, high voltage equipment can cause magnetic interference on your DSL, Phone, EFM or T1 lines. Common devices that turn on and off and are likely to cause interference are Copiers, Air Conditioning Systems, Furnaces, and Main feed lines into buildings. The goal is to avoid electromagnetic interference. Usually, running data lines in parallel to these power lines or curving them into these lines when needed, is better than doing a straight perpendicular crossing.
- Do not plug your data lines into Surge Suppressors where not needed. Although surge suppressors can save your modem, they can also cause interference on your line.
- Minimize the number of "Splits" on your data or voice line. If you split your home phone line or DSL a number of times to connect to various outlets, it is best to minimize the number of splits, and to make sure that where these splits occur the wiring is of high quality at each junction point. Each split creates an "antenna", collecting magnetic interference.
Recommendations for T1 Wire
- T1 Wire, which is a unique type of wire, should be used for any demarcation extensions past 25 feet from the Network Interface. T1 wire is a specific type of wire made for just T1 lines. It uses RJ-48 Jacks, which are different than the types of jacks used for Ethernet(ethernet uses RJ-45 Jacks).
- Using Ethernet Wire for T1 Wiring extensions: Although generally acceptable, you should never use "stranded" wire, you should use "solid core" wire, and never more than 25 feet from the Network Interface.