SH DSL INTERFACE ATM0 output description

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Jul 7th, 2007
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Im running Cisco 877 and 837 on my branch offices... both connec using ADSL lines to the same ISP at 256Kbps and 128Kbps respectively

Branch1 seems to run noticably slow,

can anyone please help me understand the following parameters of

sh dsl int atm0

>capacity used

>noise margine

>output power


>interleave speed(kbps)

the noise factors and capacity used seems to be abnormal compared to the other branch

also the Set MTU values for the problem branch is set out to be way higher then the usual 1500 as well as the delay

the bandwidth of this routers interface is set at a lower value (this router connets to the isp at 256Kbps)

while the other branch router's interface bandwidth is set at a higher value (which connects to the isp at 128Kbps)

quiet confusing... can any one help

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paolo bevilacqua Sat, 07/07/2007 - 02:04
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See, by coincidence today a lot of people is talking about ADSL problem with the 800 router. Your 877 does not appear to be running the latest firmware. You can either upgrade the router to 12.4(11)XJ3 or try upgrade the DSL fimrmare only at

The bandwidth parameter is information only, does not influence performances, and you can remove it without making any difference.

Also please reset the MTU to the default because it won't change anything.

Possibly these chances were made by someone attempting to improve performances without really knowing what he was doing.

Hope this helps, please rate post if it does!

a.shaukat Sun, 07/08/2007 - 23:39
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hmm ok il reset the MTU..

what abt the bandwidth values ?? how do i figure out what value to set .. and even on a new router this value seems to be different on different routers... whats the theory behind it like how does a router sense what bandwidth to set on this ADSL interface.... i have 640 on most of my routers

paolo bevilacqua Mon, 07/09/2007 - 01:00
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Hi, whatever value you will set for bandwidth, it won't change anything in actual router behavior or performance,as I said above it is just an informative parameter used by some routing protocols (that you don't use), so just configure "no bandwidth" and the command will go away making the configuration smaller and easier to read.

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