If up to 8 devices can share the BRI line do they all get a Terminal Endpoint Identifier or do they request one only when they need to be active? If there are only 62 (64 through 126) I think an ISDN switch would quickly find the TEI pool exhausted. Curious... dave h below is from an ISDN tutorial at www.ralphb.net/ISDN The Layer 2 establishment process is very similar to the X.25 LAP-B setup, if you are familiar with it. The TE (Terminal Endpoint) and the Network initially exchange Receive Ready (RR) frames, listening for someone to initiate a connection The TE sends an Unnumbered Information (UI) frame with a SAPI of 63 (management procedure, query network) and TEI of 127 (broadcast) The Network assigns an available TEI (in the range 64-126) The TE sends a Set Asynchronous Balanced Mode (SABME) frame with a SAPI of 0 (call control, used to initiate a SETUP) and a TEI of the value assigned by the network The network responds with an Unnumbered Acknowledgement (UA), SAPI=0, TEI=assigned. At this point, the connection is ready for a Layer 3 setup. -----Original Message----- From: Matthew Crane [mailto:[EMAIL PROTECTED]] Sent: Tuesday, September 11, 2001 1:01 PM To: [EMAIL PROTECTED] Subject: RE: Back to back ISDN [7:19414] If you follow Chucks advice the posting listed below is a good guide on how to split B channels Re: ISDN B-channel splitting posted 03/23/2000 Rick Harville wrote: > > I have received several responses sofar expressing a great > interest in the solution. Back to back ISDN over a single ISDN > line seems to be a very acceptable approach to simulating DDR. > Unfortunately, nobody seems to be able to confirm that it can > be done. A seach of archives reveals discussions but no real > verification that this is possible. The p If anyone has > actually done this please respond as there seems to be a great > interest in doing this. > > Once again, the question is, can you connect two BRI (st) > interfaces through a NT1 device using only a single ISDN line? > > I have 2 Cisco 2503's with st Bri. Im using Motorola NT1 device > with a > single U interface and 2 ST ports. I have at my disposal a > single ISDN line > from SW Bell. I would like to split the spids at the nt1 device > and practice > my DDR with only one spid on each router. Message Posted at: http://www.groupstudy.com/form/read.php?f=7&i=19469&t=19414 -------------------------------------------------- FAQ, list archives, and subscription info: http://www.groupstudy.com/list/cisco.html Report misconduct and Nondisclosure violations to [EMAIL PROTECTED]
