[SR-Users] How to correctly answer a PnP-SUBSCRIBE message

Hallo,

several telephones send a SIP-multicast SUBSCRIBE message to address 224.0.1.75 if they have no settings-URL configured and receive none over DHCP.

So I configure my kamailio server, to respond to that multicast-request. But: Although mine is working, I do feel it could be improved, since the NOTIFY packet send out is not quite as it should be …

Here is what I did (the 172.23.56.1 is my voip-vlan-address)

listen=udp:172.23.56.1:5060 advertise 192.168.1.156:5060 listen=udp:192.168.1.156:5060 advertise 192.168.1.156:5060 listen=tcp:127.0.0.1:5060

mcast="eth0" listen=udp:224.0.1.75:5060

….

if ($Ri == "224.0.1.75"){ if(is_method("SUBSCRIBE")){ xlog("L_INFO", "Received pnp-event from IP $si from User-Agent $hdr(User-Agent) und User $fU\r\n" ); sl_send_reply("200", "OK"); t_uac_send("NOTIFY", "$(ct{s.substr,1,0}{s.striptail,1})", "", "","Subscription-State: terminated;reason=timeout\r\nEvent: $hdr(Event)\r\nContent-Type: application/url\r\nFrom: $fU\r\nTo: $hdr(From)", "http://server.conf/settings-%7Bmac%7D"); }else { xlog("L_INFO", "Drop message $rm from pnp-Interface \r\n" ); } exit; }

And here are the SIP-packets I see on my server (192.168.1.156) coming from my snom-phone (192.168.1.152). My problems with the NOTIFY -packets are: 1) How do I set the Via parameters to be the same as in the OK-reply? 2) How do I send out the NOTIFY only via the 192.168.1.156 network interface? 3) May I send out the NOTIFY with the Call-ID from the SUBSCRIBE message? How?

Any help is highly appreciated Jan-Hendrik

# U 192.168.1.152:58714 -> 224.0.1.75:5060 #258 SUBSCRIBE sip:MAC%3a0004137120D8@lan SIP/2.0. Via: SIP/2.0/UDP 192.168.1.152:58714;rport. From: sip:MAC%3a0004137120D8@lan;tag=1750588964. To: sip:MAC%3a0004137120D8@lan. Call-ID: 1395386659@192.168.1.152. CSeq: 1 SUBSCRIBE. Event: ua-profile;profile-type="device";vendor="snom";model="snom760";version="8.9.3.80". Expires: 0. Accept: application/url. Contact: sip:192.168.1.152:58714. User-Agent: snom760/8.9.3.80. Content-Length: 0. .

# U 192.168.1.156:5060 -> 192.168.1.152:58714 #259 SIP/2.0 200 OK. Via: SIP/2.0/UDP 192.168.1.152:58714;rport=58714;received=192.168.1.152. From: sip:MAC%3a0004137120D8@lan;tag=1750588964. To: sip:MAC%3a0004137120D8@lan;tag=fb721cde02dffb6bb099728401306798.2f00. Call-ID: 1395386659@192.168.1.152. CSeq: 1 SUBSCRIBE. Server: kamailio (5.2.5 (x86_64/linux)). Content-Length: 0. .

# U 192.168.1.156:5060 -> 192.168.1.152:58714 #260 NOTIFY sip:192.168.1.152:58714 SIP/2.0. Via: SIP/2.0/UDP 224.0.1.75;branch=z9hG4bKf21c.917eaf36000000000000000000000000.0. To: sip:MAC%3a0004137120D8@lan;tag=1750588964. From: <MAC%3a0004137120D8>;tag=da567df9df3ac234e43969a051db4641-8cfb. CSeq: 10 NOTIFY. Call-ID: 24eaa8de01be1768-70960@172.23.56.1. Max-Forwards: 70. Content-Length: 33. User-Agent: kamailio (5.2.5 (x86_64/linux)). Subscription-State: terminated;reason=timeout. Event: ua-profile;profile-type="device";vendor="snom";model="snom760";version="8.9.3.80". Content-Type: application/url. . http://server.conf/settings-%7Bmac%7D # U 172.23.56.1:5060 -> 192.168.1.152:58714 #261 NOTIFY sip:192.168.1.152:58714 SIP/2.0. Via: SIP/2.0/UDP 224.0.1.75;branch=z9hG4bKf21c.917eaf36000000000000000000000000.0. To: sip:MAC%3a0004137120D8@lan;tag=1750588964. From: <MAC%3a0004137120D8>;tag=da567df9df3ac234e43969a051db4641-8cfb. CSeq: 10 NOTIFY. Call-ID: 24eaa8de01be1768-70960@172.23.56.1. Max-Forwards: 70. Content-Length: 33. User-Agent: kamailio (5.2.5 (x86_64/linux)). Subscription-State: terminated;reason=timeout. Event: ua-profile;profile-type="device";vendor="snom";model="snom760";version="8.9.3.80". Content-Type: application/url. . http://server.conf/settings-%7Bmac%7D # U 172.23.56.1:5060 -> 192.168.1.152:58714 #262 NOTIFY sip:192.168.1.152:58714 SIP/2.0. Via: SIP/2.0/UDP 224.0.1.75;branch=z9hG4bKf21c.917eaf36000000000000000000000000.0. To: sip:MAC%3a0004137120D8@lan;tag=1750588964. From: <MAC%3a0004137120D8>;tag=da567df9df3ac234e43969a051db4641-8cfb. CSeq: 10 NOTIFY. Call-ID: 24eaa8de01be1768-70960@172.23.56.1. Max-Forwards: 70. Content-Length: 33. User-Agent: kamailio (5.2.5 (x86_64/linux)). Subscription-State: terminated;reason=timeout. Event: ua-profile;profile-type="device";vendor="snom";model="snom760";version="8.9.3.80". Content-Type: application/url. . http://server.conf/settings-%7Bmac%7D # U 192.168.1.152:58714 -> 224.0.1.75:5060 #263 SUBSCRIBE sip:MAC%3a0004137120D8@lan SIP/2.0. Via: SIP/2.0/UDP 192.168.1.152:58714;rport. From: sip:MAC%3a0004137120D8@lan;tag=1971605806. To: sip:MAC%3a0004137120D8@lan. Call-ID: 1846532696@192.168.1.152. CSeq: 1 SUBSCRIBE. Event: ua-profile;profile-type="device";vendor="snom";model="snom760";version="8.9.3.80". Expires: 0. Accept: application/url. Contact: sip:192.168.1.152:58714. User-Agent: snom760/8.9.3.80. Content-Length: 0. .

# U 192.168.1.156:5060 -> 192.168.1.152:58714 #264 SIP/2.0 200 OK. Via: SIP/2.0/UDP 192.168.1.152:58714;rport=58714;received=192.168.1.152. From: sip:MAC%3a0004137120D8@lan;tag=1971605806. To: sip:MAC%3a0004137120D8@lan;tag=fb721cde02dffb6bb099728401306798.2f00. Call-ID: 1846532696@192.168.1.152. CSeq: 1 SUBSCRIBE. Server: kamailio (5.2.5 (x86_64/linux)). Content-Length: 0. .

# U 192.168.1.156:5060 -> 192.168.1.152:58714 #265 NOTIFY sip:192.168.1.152:58714 SIP/2.0. Via: SIP/2.0/UDP 224.0.1.75;branch=z9hG4bK201a.063839a4000000000000000000000000.0. To: sip:MAC%3a0004137120D8@lan;tag=1971605806. From: <MAC%3a0004137120D8>;tag=da567df9df3ac234e43969a051db4641-f31b. CSeq: 10 NOTIFY. Call-ID: 24eaa8de01be1768-70963@172.23.56.1. Max-Forwards: 70. Content-Length: 33. User-Agent: kamailio (5.2.5 (x86_64/linux)). Subscription-State: terminated;reason=timeout. Event: ua-profile;profile-type="device";vendor="snom";model="snom760";version="8.9.3.80". Content-Type: application/url. . http://server.conf/settings-%7Bmac%7D # U 192.168.1.152:58714 -> 192.168.1.156:5060 #266 SIP/2.0 200 Ok. Via: SIP/2.0/UDP 224.0.1.75;branch=z9hG4bKf21c.917eaf36000000000000000000000000.0;received=192.168.1.156. From: MAC:0004137120D8;tag=da567df9df3ac234e43969a051db4641-8cfb. To: sip:MAC%3A0004137120D8@lan;tag=1750588964. Call-ID: 24eaa8de01be1768-70960@172.23.56.1. CSeq: 10 NOTIFY. User-Agent: snom760/8.9.3.80. Content-Length: 0. .

# U 192.168.1.152:58714 -> 192.168.1.156:5060 #267 SIP/2.0 200 Ok. Via: SIP/2.0/UDP 224.0.1.75;branch=z9hG4bKf21c.917eaf36000000000000000000000000.0;received=192.168.1.156. From: MAC:0004137120D8;tag=da567df9df3ac234e43969a051db4641-8cfb. To: sip:MAC%3A0004137120D8@lan;tag=1750588964. Call-ID: 24eaa8de01be1768-70960@172.23.56.1. CSeq: 10 NOTIFY. User-Agent: snom760/8.9.3.80. Content-Length: 0. .

# U 192.168.1.152:58714 -> 192.168.1.156:5060 #268 SIP/2.0 200 Ok. Via: SIP/2.0/UDP 224.0.1.75;branch=z9hG4bK201a.063839a4000000000000000000000000.0;received=192.168.1.156. From: MAC:0004137120D8;tag=da567df9df3ac234e43969a051db4641-f31b. To: sip:MAC%3A0004137120D8@lan;tag=1971605806. Call-ID: 24eaa8de01be1768-70963@172.23.56.1. CSeq: 10 NOTIFY. User-Agent: snom760/8.9.3.80. Content-Length: 0. .