 T1
@comcast.net | What is at the other end of a T1 I am familiar with getting t1 equipment setup at the client end but have no idea what is at the provider end. Do they have some kind of T1 switching device, specialized routers, or just tons of routers with a gazillion serial interfaces? Also how do point to point t1's work and what kind of devices would be between the 2 points. Just curious about this, thanks for any input. |
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 tschmidtPremium,MVM
join:2000-11-12
Milford, NH
kudos:5
 ·Fairpoint Commun..
 ·Hollis Hosting
| Since no one else responded here are some links:
»www.dcbnet.com/notes/9611t1.html
»www.commsdesign.com/design_corne···16501900
»en.wikipedia.org/wiki/Digital_Signal_1
/tom |
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JoelC707Premium
join:2002-07-09
Stone Mountain, GA
kudos:4 | reply to T1
The provider end needs a T1 interface as well. Typically they would be in a large router which would then have a larger port out to the rest of their network. In other words your T1 would come into that router and go out of that router aggregated onto a GigE port or so.
A point to point T1 would have the same equipment on each end. AFAIK the central office would not have any T1 equipment on your line at their end except for maybe an amplifier. Of course this depends on how far away the two points are. This only applies if both ends are served out of the same CO. If they aren't then your signal needs to get routed to the other CO and could do so in any number of different ways. |
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 sporkmedrop the crantini and move it, sisterPremium,MVM
join:2000-07-01
Morristown, NJ
 ·Optimum Online
| reply to T1
For any large provider you'll enter their router on a larger channelized circuit, ie: a DS3, OC-3, OC-12, etc. You can aggregate thousands of T1s per inch of rack space these days...
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with every mistake we must surely be learning |
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JoelC707Premium
join:2002-07-09
Stone Mountain, GA
kudos:4 | Something I'm not really familiar with is where that aggregation happens. I suspect it doesn't happen at the CO but where else could it happen? I know when you get a DS3 or faster you don't usually get a DS3 back to the CO. Typically they bring in a SONET ring and stick a DS3 interface in the router and hand it off that way. But a T1 isn't handled that way. At my office in Atlanta we have a T1 and inside the phone room for the building there is no SONET circuit coming in though there is an RT at the edge of the property. I suspect in that case it would aggregate there but what about those fed directly from the CO? Where in the loop does theirs aggregate? |
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sporkmedrop the crantini and move it, sisterPremium,MVM
join:2000-07-01
Morristown, NJ Reviews:
·Optimum Online
| If there's not a mux in your building, then perhaps the copper goes all the way back to the CO. Once it hits the CO it will be aggregated into a larger circuit. Throughout the telco side it may pass from an OC-3 to an OC-12 or to whatever is available to get the circuit from A to Z and all the COs in between.
The ISP will receive a DS3 or higher that has their customer T1s (or T3s, or OC-3s) all muxed together on the circuit.
Wikipedia has some good stuff on how circuits are muxed together:
»en.wikipedia.org/wiki/Time-divis···iplexing (also see box on top right)
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with every mistake we must surely be learning |
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 SplitpairPremium
join:2000-07-29
Cow Towne
kudos:3 | reply to T1
said by T1 :
I am familiar with getting t1 equipment setup at the client end but have no idea what is at the provider end. For a generic point to point circuit, part by part, generically speaking it works like this from the premises back.
Your router CSU/DSU DS1 signal connects to a SmartJack aka a Highcap Remote Unit (HRU) mounted in the Network Customer Terminating Equipment (NCTE) also known as the mounting which converts the DS1 signal to a T1 for transport.
From there it is connected by either a single pair or two depending on the technology utilized to the central office repeater shelf where a Highcap Line Unit (HLU) is installed which converts the T1 signal back to a DS1 and also provides 186 or 130 volts over the copper pair(s) to power the HRU.
From the CO repeater shelf the DS1 signal along with 27 others are passed to a Digital Access Crossconnect System (DACS) or muxed up to a DS3 and then to the DACS which provides mapping of the DS1 signals and remote testing capabilities.
Out of the DACS the signal is most commonly a DS3 or higher and passed to another MUX along with other DS3’s for conversion to an OCx for interoffice transport.
At the other end the process is reversed.
Do they have some kind of T1 switching device, specialized routers, or just tons of routers with a gazillion serial interfaces? Yes, yes and yes. Depending on the type of circuit, there are fast packet switches, frame relay switches and routers.
Wayne
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If you cannot fix it with a buttset and some beanies you ain't a technician |
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