"Henry C Robertelli" <[EMAIL PROTECTED]> wrote: > I have a customer that wants me to install two (2) Panasonic TDA200 > systems on two different floors of the same building. The catch is > that he wants to tie the two systems together as illustrated in the > brochure, as if they are across town. Normally, you would use a > dedicated T1 tie line between the locations; since they are only > three floors apart, I can hardwire the line connections between the > two TDAs (note both systems are at maximum card capacity accounting > for a T1 card in one of the slots in each unit.) > > How can I interconnect the two units without purchasing a T1? What > can I use to have the bandwidth and emulate a T1 connection?
In theory, you should be able to connect the two system via a T1 cross-over cable (pins 1->5, 2->4, 4->2, 5->1) and setup all the channels as TIE lines. The systems would each think they are connected to a CO via a T1 which is then just passing along the data to the other system. The fact that there is no real CO should be mostly transparent to the TDAs. However, without the CO there is no network clock, so you'll need to use internal clocking (unless you have a clock source coming into one of the boxes from a "real" T1 or PRI). I'd imagine that you'd want to setup one TDA to use its internal clock and have the other TDA use the "network" clock. If they each use their own internal clocks instead of synchronizing on the same clock source I would expect problems such as jitter. As far as the CSUs, technically you would need one at each end. However, in reality the CSU's primary function is to act as last signal regenerator for the T1 span, so if the span is short enough it technically doesn't need any repeaters. While a CSU has settings for line build-out, I'm not sure of the exact specs for the TDA T1/PRI cards. In theory, if the distance between the TDAs is within the correct limits you could link them directly. Also, the CSUs provide the CO with remote loopback capability as well as detection of loss of signal, bipolar violations, one's density violations, etc. Since there is no CO, these features will not be utilized. That said, I can't really recommend that you don't use a CSU at each end, but technically they may not be essential to the link. Also, as far as I understand the CSU is required by the FCC for T1 links to the public network. I'm not sure how that might apply in this situation. VERY IMPORTANT: Don't forget to include appropriate surge protection for the TDAs and the T1 lines. Even though it's an interbuilding connection, you need to treat each end of the T1 as if it were an outside connection. Although this discussion relates to T1 tie lines, I would highly recommend you consider using QSIG via an ISDN-PRI instead. As far as the physical connection, it really would be a T1 link so all issues related to the interconnection would still apply. However, instead of using the T1 cards in the TDAs, put in PRI cards and set them up for QSIG operation. One TDA would be the master and the other the slave. This would really let the TDAs network well with each other and your customer would get a lot more out of the interconnection. The TDAs should be able to pass extension numbers and names between each other and really act as if they were one large system. For example, when a User1 (at ext 1001 on system 1) calls User2 (at ext 2002 on system 2) User2's phone should show "1001: User1", if User3 (at ext 2003 on system 2) answers the call User1's phone should show "2003: User3" so he/she knows who answered, etc. FYI, the TDA200 in my office is setup with a PRI card which is connect via a T1 cross-over cable to a Cisco 1760 Router. The Cisco router is configured to emulate the network side of the PRI. The Cisco connects the voice traffic to my carrier's voice gateway via our data T1 (although the voice traffic remains on their private network, never hitting the Internet). The TDA thinks it's connected to an ISDN PRI line from the CO. The span between the TDA and Cisco is about 20 feet and I do not have a CSU at the TDA (However, the T1/PRI card in the Cisco does have an integrated CSU). I hope this helps. Regards, Ian S. Goldstein NOVO OPS TECHNOLOGIES a division of Tektreve Systems, Inc. 818 Route 25A #122 Northport, NY 11768 Tel: 631-912-2600 Fax: 631-912-2605 Email: [EMAIL PROTECTED] Web: www.novoOps.com _________________________________________________________________ KX-T Mailing list --- http://kxthelp.com/ Subscription changes: http://kxthelp.com/mailman/listinfo/kxt
