wiley@dcl-cs.UUCP (Anthony John Wiley) (06/20/85)
I am developing a gateway to connect a LAN (Ethernet) to an ISDN. I therefore would like to receive any information concerning past or present work in this area. Thanks in advance, Tony Wiley. -- UUCP: ...!seismo!mcvax!ukc!icdoc!dcl-cs!wiley DARPA: wiley%lancs.comp@ucl-cs | Post: University of Lancaster, JANET: wiley@uk.ac.lancs.comp | Department of Computing, Phone: +44 524 65201 ext 4147 | Bailrigg, Lancaster, LA1 4YR, UK.
taylor@ecsvax.UUCP (Steven Taylor) (06/21/85)
Does ISDN have a defined protocol? The gateway protocol is what is needed for a gateway, and, to my knowledge, this protocol is not defined for ISDN. Instead, i think that ISDN is intended as a TRANSPORT mechanism for passing bits. I welcome anyone who knows the answer to correct me on this. I asked this question at a seminar yesterday which had as speakers, among others, Dixon Doll. Nobody there could clarify this. As a related comment though, it seems that X.25 seems to be emerging as the defacto gatewat protocol. The real question, therefore, seems to be how ISDN will interact with x.25 (level 3). Steven Taylor Distributed Networking Associates 119 Doncaster Lane Charlottesville, VA 22901 (804) 979-0656
smk@python.UUCP (S.Kuzyszyn) (06/24/85)
ISDN as defined for Basic and Primary access allows for two general types of connections: B-channel and D-channel connections. The B channel is a circuit switched channel that supports a 64 kb clear channel. This could be used for packet data between two packet switches (gateway style). In this case any protocol will do (since it is just a bit pipe, but obviously the protocols should be compatible at both ends of the pipe). The other type, a D-channel connection, supports packet data over a 16 kb (basic access), or 64 kb (primary access) channel. Because this D-channle is also used for signaling messages (e.g. for setting up B-channel connections) the entire capacity is not available for packet data (in fact, a priority scheme can give preference to the signaling messages on the D-channel). To get to the point, the D-channel will support X.25 connections at level 3 and so can be used a gateway.