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New Member

1841 + HWIC-2SHDSL poor upload throughput ** RESOLVED **


Has anyone had any experience with a Cisco 1841 and a HWIC-2SHDSL?

The problem I'm having is very very poor upload speeds on a 1Mbps/1Mbps 4 wire G.SHDSL service maxing out at ~ 10-15KBps egress.  The download speed is fine up to ~ 1Mbps ingress.

The service provider claims there is no issue with the circuit, and I'm now I'm forced to focus my attention on the router/ WIC card.

There does appear to be some OAM errors incrementing very slowly(~200 over 72 hours) on ATM PVC sub-interface, but there are no CRC errors on SHDSL controller. The SHDSL seems to be connected correctly with the right line coding/ rate as per the service provider recommended settings.

Is there anything else I could check?  See attached info

Hall of Fame Super Silver

Re: 1841 + HWIC-2SHDSL poor upload throughput

Hello Tf2-conky,

your router has no problems on the link itself

each DSL pair is working at

Line coding: 16-TCPAM, configured/actual rate: AUTO/576 kbps

but second pair stats are strange:

Previous 24 hr statistics:
                ES: 4294967295, SES: 0, CRC: 4294967040, LOSWS: 0, UAS: 0
          ATM-TC Tx: data cells: 0, Idle/Unassigned: 0
          ATM-TC Rx: data cells: 0, uncorr HEC: 0, corr HEC: 0
          ATM-TC Rx: OCD: 0, LCD start: 0, LCD end: 0

it looks like it has never been used by user traffic and errored seconds cannot be that high number in one day.

The same for CRC errors that cannot be so high in 24 h

This can be just a cosmetic bug because that number is close to 2^32-1

Hope to help


New Member

Re: 1841 + HWIC-2SHDSL poor upload throughput


I ran into a similar problem a week ago setting up a DMZ - although I don't know if this will be related. I was running speed test and was getting horrible upload speeds from my laptop. Come to find out, my NIC was hardcoded to 100 full. Upon setting the NIC back to auto the upload speed increased. The same happened from one of my DSL locations.  Hope this helps and good luck.

When you figure this out post the resolution, Conky.


New Member

Re: 1841 + HWIC-2SHDSL poor upload throughput


Forgot to set the vbr-nrt on the atm pvc

interface ATM0/1/0.33
  Pvc 0/33
  vbr-nrt 1024 1024

Now seeing ~1Mb/s down, and ~1Mb/s up

Hall of Fame Super Silver

Re: 1841 + HWIC-2SHDSL poor upload throughput

Hello Conky,

you have been kind to provide a feedback on this issue.

This makes this case complete with an happy end

Best Regards