Cisco Support Community
Showing results for 
Search instead for 
Did you mean: 

Welcome to Cisco Support Community. We would love to have your feedback.

For an introduction to the new site, click here. If you'd prefer to explore, try our test area to get started. And see here for current known issues.

New Member

No dial tone with AS5300


We are trying to do some lab testing on an AS5300 and we are having problems getting a dial tone with our test equipment. We are using an Adtran TSU100 connecting an analog (2 wire) telephone to the T1 0 port on the AS5300. The settings of this should match the adtran - which are ESF, B8ZS and I have set up a (CAS) ds0-group with just timeslot 1 in it, using fxs-loop-start as the type.

We have to use fxs as that is the only option available on both devices, but if you pick up the phone all you hear is low level noise.

I should have a voice port associated with the group, although the state of it seems to be dormant - this my be because there aren't any calls going through it or it may be the cause of the problem, but I can't seem to get it to change. Also the command 'show voice port summary' brings up an empty list which seems a little odd to me.

The other symptom we are getting is if we change the Adtran to PLAR instead of FXS-LS we get the phone to ring. If you then pick up the phone you hear dial tone for 20 seconds or so and then the line changes to a busy tone. If you dial during the dial tone part you can see the sip messages going across the network, although the call cannot be completed since both boxes are in the same state.

This suggests to me that most of the config is fine but there may be a signalling incompatibility between our adtrans (I have tried several) and the AS5300 for FXS-loop start. Either that or I am missing a configuration command, but all the example scripts I have seen specify E&M as the type, not FXS.

If anyone has got a similar situation to work or has any thoughts I would love to hear them.

Thanks in advance for your help

Mark Smith


Re: No dial tone with AS5300

Since there has been no response to your post, it appears to be either too complex or too rare an issue for other forum members to assist you. If you don't get a suitable response to your post, you may wish to review our resources at the online Technical Assistance Center ( or speak with a TAC engineer. You can open a TAC case online at

If anyone else in the forum has some advice, please reply to this thread.

Thank you for posting.