hi, i have some newbie questions about channel banks. i have an adtran act-1241 sitting around. it accepts D4 modules, and it contains a number of e&m cards. first of all, how does this thing work? a t1 contains 24 channels, and i noticed that the channel bank has space for 24 cards. what do these cards do? what are their outputs? the ones that are in there have some outputs on the front marked "test", but nothing else. there are a number of wires coming out the back (48, if i had to guess), and it has a few ports on the front which seem to be able to take in a T1. am i correct in understanding that it is the card in the bank that determines the signalling style, and not the t1? as such, is there no way that i could use it in its current configuration to have it talk with analog phones (i.e. something like t100p -> act-1241 with e&m cards -> phone)? i'm a bit unclear on the different signalling types, and their intercompatibilities. if anyone could shed any light into this, i would very much appreciate it. thanks, Ilia Mirkin imirkin@mit.edu
On Sun, 2004-09-05 at 03:10, Ilia Mirkin wrote:> hi, > > i have some newbie questions about channel banks. i have an adtran > act-1241 sitting around. it accepts D4 modules, and it contains a number > of e&m cards. > > first of all, how does this thing work? a t1 contains 24 channels, and i > noticed that the channel bank has space for 24 cards. what do these > cards do? what are their outputs? the ones that are in there have some > outputs on the front marked "test", but nothing else. there are a number > of wires coming out the back (48, if i had to guess), and it has a few > ports on the front which seem to be able to take in a T1. am i correct > in understanding that it is the card in the bank that determines the > signalling style, and not the t1? as such, is there no way that i could > use it in its current configuration to have it talk with analog phones > (i.e. something like t100p -> act-1241 with e&m cards -> phone)? i'm a > bit unclear on the different signalling types, and their > intercompatibilities. > > if anyone could shed any light into this, i would very much appreciate > it.Think of the T1 as 24 digital digital pathways. The coding of each pathway must be compatible on each end. With E&M cards, you signal with E&M and the line will work. The cards plug into a backplane where the controller routes the digital signal to the card and then optionally hook up the output from the card to a connector that consolidates many lines. Look for something that looks like an older 50 pin scsi D connector. If there is 2 RJ45 jacks on the front, and 2 50 pin D connectors on the back, then it is likely that each card controlls 2 lines each. If there is only 1 50 pin connector, then there is only 24 channels. Hope that helps. -- Steven Critchfield <critch@basesys.com>
A channel bank allows you to go from DS1 to DS0; i.e. it takes the 24 channels from a DS1 (T-1) and spins off individual DS0's. For instance, you could plug a T-1 PRI (23 channels + 1 channel for signaling) into a channel bank and get DS0 POTS (plain old telephone service) lines, which can drive a standard phone. One advantage here is a PRI T-1 is 2 or 4 wires, whereas 24 POTS lines are 48 wires (24 pair), so for a voice provider you can deliver more lines/services per pair of wire. Much the same happens on the T-1 to T-3 side with a wide bank (M13 or EZ T3 mux, ect). A T3 is 28 T-1's, so a provider can mux up to 28 T-1's from customers into a T-3, meaning fewer pairs of wire to transport or cross connect. Collocation is priced on U's of rack space or square footage and is often quite expensive at the LEC's facilities. T-3 ports are much cheaper (per DS0) than T-1 ports for the provider, who can then use a relatively cheap wide bank to get T-1's then a channel bank to get DS0's. -- James H. Edwards Routing and Security Administrator At the Santa Fe Office: Internet at Cyber Mesa jamesh@cybermesa.com noc@cybermesa.com (505) 795-7101 -------------- next part -------------- A non-text attachment was scrubbed... Name: not available Type: application/pgp-signature Size: 189 bytes Desc: This is a digitally signed message part Url : http://lists.digium.com/pipermail/asterisk-users/attachments/20040905/e43a7db0/attachment.pgp