Re: IRX-111, Bitsurfr, Bad CRC, MRU Overflow

Jeremy Porter (jerry@fc.net)
Sat, 9 Sep 1995 03:14:21 -0500 (CDT)

You don't say if you are connecting the Motorola to
a ASYNC port or a SYNC port. I've used Adtran TAs with
the V.35 to talk Cisco-Cisco and same should work with
the IRX. My understanding is the motorola uses a software
async-sync conversion, so if one end is setup for async-sync
and the other for async-async you will see problems.
Never heard of a mulitport ASYNC card for a 7000. m (Have
heard of mulitport sync cards tho..). If I was doing
sync on the cisco, and I would use 2 adtrans with V.35 cables
and plug it into the sync port on the IRX.

Using async-sync conversion is just a really bad idea.
Motorola Bitsurfr's are ISDN toys anyway.

>All,
>
>I have an IRX-111 with s0 connected to a Motorola Bitsurfr ISDN Modem setup
>as IP x.x.x.1 on a full Class C talking to a remote Bitsurfr TA connected
>to an async multiport card in a Cisco 7000.
>
>The Cisco sees everything after LCP and IPCP open as Bad CRC. Eventually,
>packet trace shows the same inbound to the IRX, after about 5-10 minutes,
>which ends in a symphony of Bad CRC, Bad Frame - MRU Overflow, and a few
>remote_slifrecv: Limited expansion room - packet lost messages that seem to
>have somehow been omitted from the pamphlet, er, documentation.
>
>Due to the bad CRC from the remote's perspective, no pings across the ISDN
>line return. The remote TA does show activity that matches the ping timing
>pattern while it is being pinged.
>
>The current IRX in use is the third IRX-111 I've tried, and the Motorola
>the second ISDN TA after an Adtran failure to talk to a Motorola async at
>115.2Kbps. I'm about to attempt to install all the equipment into an
>existing working ISDN setup as a test to rule out ISDN line problems. This
>test will also use a variety of software and hardware setups that the
>IRX-111 to test line/TA, then include the IRX to test router/TA.
>
>After all this wind, what I want is two things:
>1.) Is there anyone with a configuration anywhere near this that is working
>and who can offer some detailed assistance? My efforts with Livingston
>Technical Support seemed to result in a collective shrug. My last contact
>resulted in an escalation to Carl Rigney that hasn't materialized.
>
>2.) Can anyone offer any additional ideas to aid the testing and eventual
>use of this configuration?
>
>-Steve.
>
>

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