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How do you troubleshoot slow isdn pri connections on an access server

I have a POP ISP site using AS5800 and AS5300 .one e1 controller on both the access servers is configured for E1 PRI.

The ISP incharge complains that ISDN subscribers (using BRI connections to connect to the access server)complain of slower ISDN access speeds ,whereas the same subscribers when connect to his PC based RAS (with isdn card) have no problems.

can i have some tips/URLS in trouble shooting ISDN BRI to PRI dialin problems.


Re: How do you troubleshoot slow isdn pri connections on an acce

A few things to keep in mind:

- how is speed being determined?

- is everything else (ie network behind

the NAS and RAS, the remote users,

the servers terminating the data connections

that are used to measure throughput)


Any NAS connection has different layers

to take into consideration when comparing

throughput. Since these are sync ISDN

connections and not async modem

connections, you have one less variable.

- layer 1 - slips, errors, drops, etc.

"sh int" and "sh control e1" would

indicate if there are any issues here.

- layer 2 - PPP - if you are using Multilink,

then "show ppp mult" would confirm

if there are any lost or re-ordered

fragments. If not using MPPP, then there

should not be any issues.

- layer 3 - IP. This could be switching

problems, where we aren't switching as

fast as we could/should be. Check

"sh int stat" and "sh int switch" to

confirm that everything is at least

being fast switched.

- Other. Check the CPU on the boxes,

to make sure it is not high. Check

for alignment errors. Make sure you

are running fairly new code on the boxes.

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