We have had a problem start to crop up with ISDN customers using Netopia ISDN routers. We have been using ISDN routers for years, and have not updated any code or settings on our TC in over a year. Our HARC code is 4.1.59. Basically, we had customers using Netopia ISDN calling in telling us they cannot get their router to connect. When we 'mon ppp' during the connection, there is some sort of battle going on between the Netopia and the TC over compression. There is a stream of COMPRESSION_TYPE REQ and NAKS going back and forth. We then went into the Netopia and changed the compression method back and forth between Ascend and Stac, with no definitive conclusion. Usually after 2 or 3 power cycles, the router does connect. And sometimes after it connects and has been online for a while, it simply stops passing regular IP traffic (you can still ping it and telnet into it). I called Netopia, and after they talked to their engineers, I got this email: "I don't have the specifics regarding the Total Control compression issues. What I have found out is that the Netopia, if it is set for one type of compression, will not try a different compression, even if the NACK request from the upstream device requests a different type of compression. So, if your 3COM Access Server is set to only accept Ascend Compression, set the Netopia for Ascend Compression." I was wondering if anyone here has come across this issue. How do I verify what compression settings the TC has? Is there some setting that is forcing the TC to ONLY attempt a single compression type? Maybe someone here has found a solution for this. The Netopia routers in question are running firmware 4.8.2 - Netopia says updating the firmware does not appear to resolve this issue on their end. TIA, Scot