Problems with ISDN lines

[mspeller]

Hi,

I am having some problems with ISDN lines being utilised when I don't want them to be!

I have a 3640 (IOS ver 12.2(13)T1) router with 128k point-to-point cell-frame lines to about 30 branch routers (mostly 1603's with some 1700's and a couple of 2610's). There is also an ISDN backup line to each branch as well. All of the routers have static IP routes configured with a weighting on the route for the ISDN lines. As I understand it, that means that the routers will only utilise the ISDN lines if they can't communictate via the cell-frame lines. What is happening is that at random times I will find that 1 or more (upto around 12) branches will be using both their Cell-frame line and ISDN line at the same time. The 3640 has a PRI, all of the branch routers use BRI's. One branch using a 2610 router has 2 BRI's and will quite frequently use all 4 channels. Usually it is the branch router which initiates the call, although not always. The most puzzling thing for me is that the bandwidth demands should not be especially high since we are using a complete Citrix environment. The servers are at the same physical location as the 3640, and all of the branches use 10 Wyse terminals along with 2 laser printers and 1 dot-matrix printer.

A majority of the time the ISDN lines remain un-used, they are only required as backup in the event that a cell-frame line goes down. However every now and again I will find that the ISDN lines are being used as described above. I have spent quite some time checking the routers and speaking to BT engineers and in a majority of cases there has been no reported disruption on the cell-frame lines. Obviously I can't be sure how often the ISDN lines are being used and how long they stay up for as I can't monitor the routers continuously, but I am puzzled as to why they are being used when the cell-frame lines are up. Can anyone shed any light on this problem for me?

Many thanks

Martin Speller

[stomasko]

Try verifying your config files with the ones on the link below. I believe this is the type of setup you are looking for, ISDN only used when the main network is down. Hope this is helpful.

http://www.cisco.com/en/US/products/sw/iosswrel/ps1835/products_configuration_guide_chapter09186a00800dc81d.html

Steve

[olivialiam072]

This is a common issue in the ISDN lines configuration which I faced by Women in Construction melbourne. As most of the female staff is managing different computer activities. And they were facing the same issue. Then I contact to the support team and they hired someone from the foriegn country so that he could fixed this issue. As due to this issue the report of our inspection projects were in pending but the person which we hired for fixing it did his work very quickly and fixed the issue in just 3 days. So you could also hire someone for fixing this issue.

[Georg Pauwen]

@olivialiam072 Is this some sort of lorem ipsum text ?

[Georg Pauwen]

Hello.

post the full running configs (sh run) of the routers in question...

[weldongalloway]

This is a common issue with ISDN line configurations, and I encountered something similar with Bottleneck Checker. Our team, primarily managed by female staff, was dealing with the same problem across multiple systems. After struggling to resolve it internally, we decided to bring in an external expert from abroad. The hired specialist quickly identified the root cause and resolved the issue in just three days. This prompt solution was critical, as it allowed us to catch up on delayed inspection reports. If you're facing a similar situation, hiring a skilled professional might be the fastest way to fix the problem.