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Re: T1 short-haul vs. long-haul
At 08:25 AM 7/21/2004, you wrote:
Normally in Europe when you order an E1 (G.703) connection the Telco delivers aYou can travel up to 655 ft. with a T1 cable from the NTU which the phone company will drop at your site. According to the letter of the specs, you are supposed to use "T1 cable" two 22AWG pairs individually shielded to prevent cross-talk. In practice, we have extended DMarcs up to 200-300 feet with regular Cat 3/4/5/6 cable and have never had any problems or out of spec. cross-talk as a result.
Same basic procedure, the telco will drop off a T1 smartjack (NTU) and you will plug your equipment into this box.o How is this normally done in the US by the Telcos for T1 lines?
o I assume the difference between T1 short-haul and long-haul is the cable length.Most modern equipment allows you to set the tx/rx gain on the DSU. We use mostly Cisco WIC-1DSU-T1 cards which fit into any 1600/1700/2600/3600/3700 router and provide better diagnostic capabilities than older standalone DSUs. It is also nice to have a single box rather than two power cables and a serial cable to worry about at a remote site.
This is one of the "features" of the new WIC-1DSU-T1-V2. It seems that some DSUs can be powered by the telco remotely. In 15 years of working in communications, I've never seen this, but that doesn't mean it isn't used by some remote telco using old style T1 without HDSL or HDSL2 running over the line.o What is "Wet T1 Capable"? What is it used for and who needs this?
In almost all cases today, the T1 spam itself will be powered from the CO and the smartjack will convert 2 HDSL pairs or one HDSL2 pair to a T1 signal with distinct TX/RX pairs.
Does anyone else have more/better info?
If the service is available in your office areas, make sure to specify ESF framing and B8ZS encoding when you order the line. AMI is robbed bit signaling and will give you 24 56k channels instead of the 24 64k channels of B8ZS. The biggest problem is keeping after the carrier to actually install the circuit.o What else is important in dealings with US Telcos when ordering and using T1 leased-line services?
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