Greetings all:

Having a weird issue with BLF relay from Kamailio <-> FreeSWITCH on the
EC2 network.

Set-up:

Natted Client <-> Natted Kamailio <-> Natted FreeSWITCH

Kamailio has a public advertised IP (Amazon Cloud) and sends to
FreeSWITCH's public IP (Amazon Cloud). Clients register to Kamailio and
the registration sent to FreeSWITCH (via uac).

What works:

When a client registers to kamailio via UDP, all works beautifully.

What doesn't work:

When a client registers to kamailio via TCP, a NOTIFY is sent with
almost no information.

Example of UDP traffic:

U 2015/03/26 22:12:30.483767 FREESWITCH_IPADDR:5060 ->
KAMAILIO_NAT_IPADDR:5060
NOTIFY sip:3000@CLIENT_PUBLIC_IPADDR:42477;line=51w5wsns SIP/2.0.
Via: SIP/2.0/UDP FREESWITCH_IPADDR;rport;branch=z9hG4bKv7X88FmKg04UF.
Route: <sip:KAMAILIO_PUBLIC_IPADDR>;lr=on;ftag=xew5nmpr9q;nat=yes.
Record-Route: <sip:KAMAILIO_PUBLIC_IPADDR>;lr=on;ftag=xew5nmpr9q;nat=yes.
Max-Forwards: 70.
From: <sip:3000@CLIENT_DOMAIN;user=phone>;tag=YF4HMSQNlOOt.
To: <sip:3000@CLIENT_DOMAIN>;tag=xew5nmpr9q.
Call-ID: 3134323734303730333531303039-ji1sw7gyd7uj.
CSeq: 366877453 NOTIFY.
Contact: <sip:3000@FREESWITCH_IPADDR:5060>.
User-Agent:
FreeSWITCH-mod_sofia/1.4.18+git~20150312T185523Z~4eed221b69~64bit.
Allow: INVITE, ACK, BYE, CANCEL, OPTIONS, MESSAGE, INFO, UPDATE,
REGISTER, REFER, NOTIFY, PUBLISH, SUBSCRIBE.
Supported: timer, path, replaces.
Event: dialog.
Allow-Events: talk, hold, conference, presence, as-feature-event,
dialog, line-seize, call-info, sla, include-session-description,
presence.winfo, message-summary, refer.
Subscription-State: active;expires=2686.
Content-Type: application/dialog-info+xml.
Content-Length: 546.
.
<?xml version="1.0"?>
<dialog-info xmlns="urn:ietf:params:xml:ns:dialog-info" version="14"
state="full" entity="sip:3000@CLIENT_DOMAIN">
<dialog id="312b3bee-d405-11e4-a8b6-41b65d0bd045" direction="initiator">
<state>confirmed</state>
<local>
<identity display="3000">sip:3000@CLIENT_DOMAIN</identity>
<target uri="sip:3000@CLIENT_DOMAIN">
<param pname="+sip.rendering" pvalue="yes"/>
</target>
</local>
<remote>
<identity display="*98">sip:*98@CLIENT_DOMAIN</identity>
<target uri="sip:**3000@CLIENT_DOMAIN"/>
</remote>
</dialog>
</dialog-info>

U 2015/03/26 22:12:30.483877 KAMAILIO_NAT_IPADDR:5060 ->
CLIENT_PUBLIC_IPADDR:42477
NOTIFY sip:3000@CLIENT_PUBLIC_IPADDR:42477;line=51w5wsns SIP/2.0.
Via: SIP/2.0/UDP
KAMAILIO_PUBLIC_IPADDR:5060;branch=z9hG4bKfabf.4908255bf1623d250ddf7d51a3b49fb8.0.
Via: SIP/2.0/UDP
FREESWITCH_IPADDR;received=FREESWITCH_IPADDR;rport=5060;branch=z9hG4bKv7X88FmKg04UF.
Record-Route: <sip:KAMAILIO_PUBLIC_IPADDR>;lr=on;ftag=xew5nmpr9q;nat=yes.
Max-Forwards: 69.
From: <sip:3000@CLIENT_DOMAIN;user=phone>;tag=YF4HMSQNlOOt.
To: <sip:3000@CLIENT_DOMAIN>;tag=xew5nmpr9q.
Call-ID: 3134323734303730333531303039-ji1sw7gyd7uj.
CSeq: 366877453 NOTIFY.
Contact: <sip:3000@FREESWITCH_IPADDR:5060>.
User-Agent:
FreeSWITCH-mod_sofia/1.4.18+git~20150312T185523Z~4eed221b69~64bit.
Allow: INVITE, ACK, BYE, CANCEL, OPTIONS, MESSAGE, INFO, UPDATE,
REGISTER, REFER, NOTIFY, PUBLISH, SUBSCRIBE.
Supported: timer, path, replaces.
Event: dialog.
Allow-Events: talk, hold, conference, presence, as-feature-event,
dialog, line-seize, call-info, sla, include-session-description,
presence.winfo, message-summary, refer.
Subscription-State: active;expires=2686.
Content-Type: application/dialog-info+xml.
Content-Length: 546.
.
<?xml version="1.0"?>
<dialog-info xmlns="urn:ietf:params:xml:ns:dialog-info" version="14"
state="full" entity="sip:3000@CLIENT_DOMAIN">
<dialog id="312b3bee-d405-11e4-a8b6-41b65d0bd045" direction="initiator">
<state>confirmed</state>
<local>
<identity display="3000">sip:3000@CLIENT_DOMAIN</identity>
<target uri="sip:3000@CLIENT_DOMAIN">
<param pname="+sip.rendering" pvalue="yes"/>
</target>
</local>
<remote>
<identity display="*98">sip:*98@CLIENT_DOMAIN</identity>
<target uri="sip:**3000@CLIENT_DOMAIN"/>
</remote>
</dialog>
</dialog-info>

Example of TCP failure:

U 2015/03/26 22:19:45.963196 FREESWITCH_IPADDR:5060 ->
KAMAILIO_NAT_IPADDR:5160
NOTIFY sip:3001@CLIENT_PUBLIC_IPADDR:5065;transport=tcp SIP/2.0.
Via: SIP/2.0/UDP FREESWITCH_IPADDR;rport;branch=z9hG4bKjH5Nt8QKUU9Sp.
Route:
<sip:KAMAILIO_PUBLIC_IPADDR:5160;r2=on;lr=on;ftag=9jSFr02tgvHym;nat=yes>.
Route:
<sip:KAMAILIO_PUBLIC_IPADDR:5160;transport=tcp;r2=on;lr=on;ftag=9jSFr02tgvHym;nat=yes>.
Max-Forwards: 70.
From: "3000" <sip:3000@CLIENT_DOMAIN>;tag=9jSFr02tgvHym.
To: <sip:3001@CLIENT_DOMAIN>;tag=1dba0f3ceb32436bi0.
Call-ID: 0882b1bc-4ea9-1233-f3a2-12e513dfd8f0.
CSeq: 73368127 NOTIFY.
Contact: <sip:mod_sofia@FREESWITCH_IPADDR:5060>.
User-Agent:
FreeSWITCH-mod_sofia/1.4.18+git~20150312T185523Z~4eed221b69~64bit.
Allow: INVITE, ACK, BYE, CANCEL, OPTIONS, MESSAGE, INFO, UPDATE,
REGISTER, REFER, NOTIFY, PUBLISH, SUBSCRIBE.
Supported: timer, path, replaces.
Event: refer;id=101.
Allow-Events: talk, hold, conference, presence, as-feature-event,
dialog, line-seize, call-info, sla, include-session-description,
presence.winfo, message-summary, refer.
Subscription-State: terminated;reason=noresource.
Content-Type: message/sipfrag;version=2.0.
Content-Length: 16.
.
SIP/2.0 200 OK.

T 2015/03/26 22:19:45.963407 KAMAILIO_NAT_IPADDR:5160 ->
CLIENT_PUBLIC_IPADDR:5065 [AP]
NOTIFY sip:3001@CLIENT_PUBLIC_IPADDR:5065;transport=tcp SIP/2.0.
Via: SIP/2.0/TCP
KAMAILIO_PUBLIC_IPADDR:5160;branch=z9hG4bKe961.8d1f19f1acc0295e5e397afa76910115.0.
Via: SIP/2.0/UDP
FREESWITCH_IPADDR;received=FREESWITCH_IPADDR;rport=5060;branch=z9hG4bKjH5Nt8QKUU9Sp.
Max-Forwards: 69.
From: "3000" <sip:3000@CLIENT_DOMAIN>;tag=9jSFr02tgvHym.
To: <sip:3001@CLIENT_DOMAIN>;tag=1dba0f3ceb32436bi0.
Call-ID: 0882b1bc-4ea9-1233-f3a2-12e513dfd8f0.
CSeq: 73368127 NOTIFY.
Contact: <sip:mod_sofia@FREESWITCH_IPADDR:5060>.
User-Agent:
FreeSWITCH-mod_sofia/1.4.18+git~20150312T185523Z~4eed221b69~64bit.
Allow: INVITE, ACK, BYE, CANCEL, OPTIONS, MESSAGE, INFO, UPDATE,
REGISTER, REFER, NOTIFY, PUBLISH, SUBSCRIBE.
Supported: timer, path, replaces.
Event: refer;id=101.
Allow-Events: talk, hold, conference, presence, as-feature-event,
dialog, line-seize, call-info, sla, include-session-description,
presence.winfo, message-summary, refer.
Subscription-State: terminated;reason=noresource.
Content-Type: message/sipfrag;version=2.0.
Content-Length: 16.
.
SIP/2.0 200 OK.

My thoughts is that this is on FreeSWITCH, just not sending a NOTIFY
with anything of value. That being said, I'd love to know if (a) anyone
else has had this issue or (b) if someone has a different theory.

Thanks!