From d11b3119921374357378aa80170f9185ef8afa19 Mon Sep 17 00:00:00 2001 From: Guy Harris Date: Thu, 29 Mar 2001 07:46:08 +0000 Subject: Fix a typo. Put in a comment about NLPIDs. svn path=/trunk/; revision=3205 --- packet-lmi.c | 31 +++++++++++++++++++++++++++++-- 1 file changed, 29 insertions(+), 2 deletions(-) (limited to 'packet-lmi.c') diff --git a/packet-lmi.c b/packet-lmi.c index a2841b24f7..6e07e878c7 100644 --- a/packet-lmi.c +++ b/packet-lmi.c @@ -2,7 +2,7 @@ * Routines for Frame Relay Local Management Interface (LMI) disassembly * Copyright 2001, Jeffrey C. Foster * - * $Id: packet-lmi.c,v 1.1 2001/03/23 19:22:02 jfoster Exp $ + * $Id: packet-lmi.c,v 1.2 2001/03/29 07:46:08 guy Exp $ * * Ethereal - Network traffic analyzer * By Gerald Combs @@ -67,6 +67,33 @@ static int hf_lmi_act = -1; static gint ett_lmi = -1; static gint ett_lmi_ele = -1; +/* + * XXX - 0x09 means Q.2931 in some places, and Q.933 says 0x08 is the + * NLPID for Q.933. + * + * However, RFC 2427 also says that an NLPID of 0x08 is used for + * protocols that have neither an NLPID nor a SNAP encapsulation. + * + * What's the deal here? Is 0x08 for Q.933, and 0x09 for LMI, with + * Q.933 used for full blown "phone call"-style signaling and LMI used + * only for PVC status information? The IBM reference above says + * that 0x08 is used for LMI. + * + * The Linux 2.2.14 "drivers/net/comx-proto-fr.c" has 0x08 as + * NLPID_Q933_LMI and 0x09 as NLPID_CISCO_LMI. The page at + * + * http://dtool.com/gang.html + * + * speaks of "ANSI or ANSI Annex D or ITU-T Annex A" LMI, + * "Cisco" or "Gang of Four" LMI, and "Q933A (ITU-T)" or "Annex-A" + * LMI. + * + * If 0x08 is for Q.933, how do you distinguish the Q.931-style + * signaling packets from the RFC 2427 encapsulation? Require a + * call reference value of 0, which would presumably not be valid + * for the first octet of an L2 protocol ID? RFC 2427 appears to + * be silent on this. + */ #define NLPID_LMI 0x09 /* NLPID value for LMI */ #ifdef _OLD_ @@ -114,7 +141,7 @@ static const value_string pvc_status_new_str[] = { static const value_string pvc_status_act_str[] = { {0x00, "PVC is Inactive"}, - {0x01, "PVC is Acive"}, + {0x01, "PVC is Active"}, { 0, NULL } }; -- cgit v1.2.3