TA908 and SIP SUBSCRIBE message for message waiting

[Anonymous]

I have a 908 in behind an NEC phone system.  The NEC sees this as a SIP station side device and the FXS ports are configured as user accounts.  Everything is working good but one thing.  The analog phones need to have some sort of message waiting.  In the registration process, we notice the 908 does not send a subscribe packet such as the SIP softphones do.  After a message is left, no notify message appears.  I am told from NEC the SIP users MUST send a subscribe packet for the PBX to properly send the MWI back to the 908.  How would this be overcome if at all? 

[Anonymous]

Hello and thanks for posting to our forum.

The NEC will have to send the SIP Notify for Message Waiting Indication to the TA 900, as the TA 900 will not send a SIP Subscribe for MWI. 

Regards,

Geoff

[Anonymous]

What I get back from NEC tech support is, they require the SIP SUBSCRIBE message while registering for them to send SIP NOTIFY msgs.  If they do not get it, it will not send it.  Is the SUBSCRIBE msg a standard item for SIP user agents to send?  I say standard knowing SIP is implemented in many ways, but I am curious as to why the 908 does not send it.  Thank you

[Anonymous]

Also, if in fact the NEC sent to the NOTIFY, what will the 908 do with it?  Will it generate stutter tone to the FXS port it's assigned to (or also neon option)?

[Anonymous · Accepted solution]

Hello,

The analog FXS port can be set to Lamp, Dial-tone, or both.  MWI would work if the NEC just sent the Notify.  The TA 900 series will only do implicit subscriptions, meaning the PBX/Switch assumes we are subscribed to MWI.  In this case, the NEC does explicit subscription, where it waits for the ADTRAN to send a Subscribe before it will send a Notify with MWI.

Regards,

Geoff

[Anonymous]

I went ahead and flagged this post as “Assumed Answered.” If any of the responses on this thread assisted you, please mark them as either Correct or Helpful answers with the applicable buttons. This will make them visible and help other members of the community find solutions more easily. If you still need assistance, I would be more than happy to continue working with you on this - just let me know in a reply.

Regards,

Geoff