I'm pretty sure that the Cisco WIC-1DSU-56K will do 56K and Clear Channel
64Kbps equally well, having configured both in the past. The 16xx series
routers that have the 56K interface soldered onto the mainboard will
*only* do 56K.
I have seen many times a "64K circuit" cause confusion. Sometimes the
telco drops a t1 with a single ds0 enabled, sometimes they drop a DDS
line, but don't config it for Clear Channel mode.
If you do create a loopback plug as described and want to test the
router's wic be aware that it won't loop up in CC64 mode, only in 56K DDS
mode. The Cisco manuals talk about this - when you lab up 2 56K wics back
to back in a testbed be sure to set them for 56K.
On Sun, 3 Feb 2002, Richard Stanaford wrote:
>
>
> Sorry for the late response... I am just getting caught up..
>
> Are you certain the WIC card they are using will run at 64Kbps? I used
> to work at a communications provider (agreeing with the Nameless thing)
> where I built, tested, and turned up Frame Relay circuits over DDS, DS1,
> DS3, etc.
>
> I've seen people order a 64Kbps line, have said line installed and
> tested at 64Kbps, and end up having the thing not run because they threw
> in a 56Kbps WIC in the router.
>
> I imagine why the circuit will only sync when set for 64Kbps is because
> that is how the line was provisioned.
>
> It's been a while since I've tested these but I'd imagine you would be
> seeing massive CRC errors when trying to run the WIC at 56Kbps.
>
> These days, when you are dealing with DDS circuits, you usually cannot
> throw a logical loop on the NIU. You can on the OCU, but that's in the
> CO and not on the cust prem, so it doesn't help you.
>
> You might fashion a DDS loopback plug (loop pin 1 to pin 7 and loop pin
> 2 to pin 8) and stick it in to the NIU (wherever the router is picking
> up the circuit). If Telco can run SP5 (or whatever) clean to that
> hard-loop at 64Kbps, then it's safe to assume you've either got a bad
> patch cable or a bad WIC, if it still won't run while configured for
> 64Kbps.
>
> Good luck,
> -Richard
>
>
> On Wed, Jan 16, 2002 at 12:01:02PM -0600, David P. Maynard wrote:
> >
> > One of our customers ordered a 64Kbps point-to-point circuit between their
> > main site in TX and a remote site in FL. They are using WIC-1DSU-56K
> > cards on both ends. Their circuit provider (who shall remain nameless)
>
--C. Jon Larsen Chief Technology Officer, Richweb.com (804.307.6939) SMTP: jlarsen@richweb.com (http://richweb.com/cjl_pgp_pub_key.txt)
Richweb.com: Designing Open Source Internet Business Solutions since 1995 Building Safe, Secure, Reliable Cisco-Powered Networks since 1995
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