No Reponse to VM SUBSCRIBE message?

[BJReplay]

OK, quick background...

VM is working for me - calls get fowarded to VM on no answer by the SPA, and I get VMWI and stutter tone MWI when there's a VM. All Good.

However, I noticed a fair amount of traffic, and a significant excess of outgoing SIP messages to incoming SIP messages, so I thought i'd throw a syslogger at the problem.

What appears to be happening is that the SPA is trying to subscribe to VM, but getting no response to the subscribes. It sends 15 subscribes (or thereabouts) over 60 seconds, then waits 30 seconds before trying again. I imagine the voxalot servers don't appreciate this.

However, usually in the middle of all this, voxalot nicely sends a notify - which the SPA acks.

Have I stuffed up my SPA settings to cause this, or should voxalat be acking the subscribes? Is the problem that the call id in my sub requests is an internal IP addy (192.168.1.3) or is that a red herring?

PM for account details if you want to debug - I've removed them from the syslog data.

[0:5060]->71.13.117.133:5060
SUBSCRIBE sip:111111@voxalot.com SIP/2.0
Via: SIP/2.0/UDP my.external.ip.addy:5060;branch=z9hG4bK-d786e18d
From: MyUserName <sip:111111@voxalot.com>;tag=c6a3dd958a4ab3eb
To: MyUserName <sip:111111@voxalot.com>
Call-ID: 943165d-f78391c3@192.168.1.3
CSeq: 56806 SUBSCRIBE
Max-Forwards: 70
Authorization: Digest username="111111",realm="voxalot.com",nonce="
aHexEncodedNonce",uri="sip:111111@voxalot.com",algorithm=MD5,response
="aHexEncodedResponse"
Contact: MyUserName <sip:111111@my.external.ip.addy:5060>
Expires: 600
Event: message-summary
User-Agent: Linksys/SPA3000-3.1.10(GWd)
Content-Length: 0

.... Repeated 5 times over 20 seconds ....

Then, in the middle I get:

[0:5060]<<71.13.117.133:5060
NOTIFY sip:111111@my.external.ip.addy:5060 SIP/2.0
Max-Forwards: 10
Record-Route: <sip:71.13.117.133;lr=on>
Via: SIP/2.0/UDP 71.13.117.133;branch=z9hG4bKf9a4.c282f903.0
Via: SIP/2.0/UDP 71.13.117.133:44796;branch=z9hG4bK.51e9aaca;rport=44796;alias
Via: SIP/2.0/UDP 71.13.117.133:5060
From: <sip:vmserver@voxalot.com>
To: <sip:111111@voxalot.com>
Contact: <sip:111111@71.13.117.133>
Call-ID: aHexEncodedCallID@71.13.117.133
CSeq: 1 NOTIFY
User-Agent: VoiceMail
Event: message-summary
Content-Type: application/simple-message-summary
Content-Length: 81
P-hint: usrloc applied

Messages-Waiting: no
Message-Account: sip:111111@voxalot.com
Voice-Message: 0/0

To which the SPA responds....

[0:5060]->71.13.117.133:5060
SIP/2.0 200 OK
To: <sip:111111@voxalot.com>;tag=d64ff3f3f69f1819i0
From: <sip:vmserver@voxalot.com>
Call-ID: aHexEncodedCallID@71.13.117.133
CSeq: 1 NOTIFY
Via: SIP/2.0/UDP 71.13.117.133;branch=z9hG4bKf9a4.c282f903.0
Via: SIP/2.0/UDP 71.13.117.133:44796;branch=z9hG4bK.51e9aaca;rport=44796;alias
Via: SIP/2.0/UDP 71.13.117.133:5060
Record-Route: <sip:71.13.117.133;lr=on>
Server: Linksys/SPA3000-3.1.10(GWd)
Content-Length: 0

But it keeps trying to subscribe:

[0:5060]->71.13.117.133:5060
SUBSCRIBE sip:111111@voxalot.com SIP/2.0
Via: SIP/2.0/UDP my.external.ip.addy:5060;branch=z9hG4bK-d786e18d
From: MyUserName <sip:111111@voxalot.com>;tag=c6a3dd958a4ab3eb
To: MyUserName <sip:111111@voxalot.com>
Call-ID: 943165d-f78391c3@192.168.1.3
CSeq: 56806 SUBSCRIBE
Max-Forwards: 70
Authorization: Digest username="111111",realm="voxalot.com",nonce="
aHexEncodedNonce",uri="sip:111111@voxalot.com",algorithm=MD5,response
="aHexEncodedResponse"
Contact: MyUserName <sip:111111@my.external.ip.addy:5060>
Expires: 600
Event: message-summary
User-Agent: Linksys/SPA3000-3.1.10(GWd)
Content-Length: 0

.... Repeated 5 times over 20 seconds ....

Then issues this message

[0]SUBS:Failed(55). Retry in 30s