dwall@hpindda.HP.COM (Darren Wall) (04/02/88)
Is it an "accepted practice" to use 0xCC in the first byte of Call User Data in an X.25 CALL REQUEST Packet for routing IP data over an X.25 Link? I know that for DDN Standard Services it's required, but I had thought that everyone did it whether DDN Standard is being requested or not. The reason that I ask is I noticed that Cisco Box that we have does not use any Call User Data in it's CALL REQUEST Packet. The Cisco I am using is: System Bootstrap, Version 3.0(3), copyright (c) 1987 by cisco Systems, Inc. ASM/AGS System, Version 6.1(343), compiled Wed 11-Nov-87 15:58 Darren Wall
postel@VENERA.ISI.EDU (04/05/88)
Darren Wall: See RFC-877. --jon.
dwall@hpindda.HP.COM (Darren Wall) (04/06/88)
> > Is it an "accepted practice" to use 0xCC in the first byte of > Call User Data in an X.25 CALL REQUEST Packet for routing IP > data over an X.25 Link? I know that for DDN Standard Services > it's required, but I had thought that everyone did it whether > DDN Standard is being requested or not. > Please note the "accepted practice" phrase. The reason I posted the note was to find out if other people knew of implementations that did the same thing. After talking with my Corporate Telecommunications Department, I understand that this is a bug with the particular version of firmware that I had. However, this was the first node of many that I need to set up and I was shocked to find that my assumptions were wrong. The 0xCC flag is important when nodes need simultaneous X.25 and IP access. Darren Wall
ahill@CC7.BBN.COM ("Alan R. Hill") (04/09/88)
The field you are discussing is the protocol ID field and should be set to the appropriate value for the protocol you intend to utilize. The BBN PSNs currently support 0xCC for DDN Standard Service (Interoperable) and 0xCD for ISO. Alan
philipp@LARRY.MCRCIM.MCGILL.EDU (Philip Prindeville [CC]) (04/10/88)
I'm sure that Jon Postel already mentioned this but someone seems to have missed it: The 0xCC in the Call User Data is required in RFC-877, and mentioned in [I think] CSNET report DN-5. -Philip