Subject: PPP Stac LZS Comperssion - CISCO Interoperability.

From: Michael Liwerant <[email-masked]>
Date: Sun, 11 Jan 1998 09:39:31 +0200

Hi All,

I'll thank anyone's help in the next issue: 

We are trying to check interoperability of our implementation of PPP
Stac LZS Comperssion with CISCO 4000 S/W Ver. 10.3(18) and we
encountering the following problems:

1) History synchronization mechanism - It seems that cisco does not
support 'reset_request' and 'reset_ack'. when cisco gets a
'reset_request' it returns 'code_reject', and when cisco recieves an out
of order frame it renegotiate the protocol (CCP) instead of sending a
'reset_request' frame.

2) Incompatability of the Stac LZS packets format  - We have negotiated
(successfuly) a single History Count and sequence number Check Mode. In
such a case, RFC1974 specifies that the History Number field is removed
from the Stac LZS packet and Check Value field comprises one octet. It
seems that CISCO inserts a leading zero byte before the History Nubmer
field. 

Thanx for your reply - Michael.