ok,
I think I've found what caused the 30 minutes dropped calls
it seems that the linksys/sipura ATA does not support RFC 4028 Session Timer;
however, the dropped calls were due to the missing?!? session refresh from the UAS
here's the SIP convo:
Code:
Jan 4 11:51:10 000E08BBB0E8 [0:5062]->74.52.58.50:5060
Jan 4 11:51:10 000E08BBB0E8 [0:5062]->74.52.58.50:5060
Jan 4 11:51:10 000E08BBB0E8 INVITE sip:PROTECTED@sip.voipwelcome.com SIP/2.0
Via: SIP/2.0/UDP 192.168.1.205:5062;branch=z9hG4bK-f5babb26
From: PROTECTED <sip:PROTECTED@sip.voipwelcome.com>;tag=20475daff076053eo0
To: <sip:PROTECTED@sip.voipwelcome.com>
Remote-Party-ID: PROTECTED <sip:PROTECTED@sip.voipwelcome.com>;screen=yes;party=calling
Call-ID: be9cc743-deab88ba@192.168.1.205
CSeq: 101 INVITE
Max-Forwards: 70
Contact: PROTECTED <sip:PROTECTED@PROTECTED:5062>
Expires: 240
User-Agent: Linksys/SPA1001-3.1.19(SE)
Content-Length: 384
Allow: ACK, BYE, CANCEL, INFO, INVITE, NOTIFY, OPTIONS, REFER
Supported: x-sipura, replaces
Content-Type: application/sdp
--------------(SDP not shown)--------------
Jan 4 11:51:16 000E08BBB0E8 [0:5062]<<74.52.58.50:5060
Jan 4 11:51:16 000E08BBB0E8 [0:5062]<<74.52.58.50:5060
Jan 4 11:51:16 000E08BBB0E8 SIP/2.0 200 OK
Via: SIP/2.0/UDP 192.168.1.205:5062;rport=5062;received=PROTECTED;branch=z9hG4bK-fa29c5ee
From: PROTECTED <sip:PROTECTED@sip.voipwelcome.com>;tag=20475daff076053eo0
To: <sip:PROTECTED@sip.voipwelcome.com>;tag=gK0ecbcd2f
Call-ID: be9cc743-deab88ba@192.168.1.205
CSeq: 102 INVITE
Record-Route: <sip:74.52.58.50:5060;lr=on;ftag=20475daff076053eo0>
Accept: application/sdp, application/isup, application/dtmf, application/dtmf-relay, multipart/mixed
Contact: <sip:PROTECTED@PROTECTED:5060;nat=yes>
Allow: INVITE,ACK,CANCEL,BYE,REGISTER,REFER,INFO,SUBSCRIBE,NOTIFY,PRACK,UPDATE,OPTIONS
Supported: timer
Session-Expires: 1800;refresher=uas
Content-Length: 194
Content-Disposition: session; handling=required
Content-Type: application/sdp
--------------(SDP not shown)--------------
even though the UAC (ATA)'s INVITE did not include:
nor specified:
Code:
Min-SE
Session-Expires: 1800;refresher=uas
notice server resp to the INVITE includes:
Code:
Supported: timer
Session-Expires: 1800;refresher=uas
Content-Length: 194
Content-Disposition: session; handling=required
row 1 in Table 2: UAS Behavior in section 9. UAS Behavior in the RFC 4028 Session Timer says: (my interpretation) in the case where UAC's INVITE does not include session timer, nor refresher in its header; the UAS is responsible for refreshing/resetting the session timer
Code:
UAC supports? refresher parameter refresher parameter
in request in response
-------------------------------------------------------
N none uas
N uac NA
N uas NA
Y none uas or uac
Y uac uac
Y uas uas
Table 2: UAS Behavior
now very looks good as far as the UAS resp concerns, but there was no refreshing seen in the log...
the UAS dropped the session just right before 1800sec session expire time - it did what it was called for by the RFC
Code:
Jan 4 12:21:16 000E08BBB0E8 [0:5062]<<74.52.58.50:5060
Jan 4 12:21:16 000E08BBB0E8 [0:5062]<<74.52.58.50:5060
Jan 4 12:21:16 000E08BBB0E8 BYE sip:PROTECTED@75.75.82.60:5062;nat=yes SIP/2.0
Record-Route: <sip:74.52.58.50;lr=on;ftag=gK0ecbcd2f>
Via: SIP/2.0/UDP 74.52.58.50;branch=z9hG4bK1abc.47433cc2.0
Via: SIP/2.0/UDP PROTECTED:5060;rport=5060;branch=z9hG4bK0eB936466bdb6b101ce
From: <sip:PROTECTED@sip.voipwelcome.com>;tag=gK0ecbcd2f
To: "PROTECTED" <sip:PROTECTED@sip.voipwelcome.com>;tag=20475daff076053eo0
Call-ID: be9cc743-deab88ba@192.168.1.205
CSeq: 2622 BYE
Max-Forwards: 69
Content-Length: 0
could someone confirm my finding?
the easiest way is to sniff the SIP convo (VOIPo GS ATA) and look for the refresh(es) (UPDATE/re-INVITE) - should take place at 1/2 the "Session-Expires"'s value (RFC 4028 recommendation)
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