rfc3398
http://www.rfc-editor.org/rfc/rfc3398.txt5.1 'Transparent' Transit of ISUP Messages
To allow gateways to take advantage of the full range of services
afforded by the existing telephone network when placing calls from
PSTN to PSTN across a SIP network, SIP messages MUST be capable of
transporting ISUP payloads from gateway to gateway. The format for
encapsulating these ISUP messages is defined in [3].
SIP user agents which do not understand ISUP are permitted to ignore
these optional MIME bodies.
5.2 Understanding MIME Multipart Bodies
In most PSTN interworking situations, SIP message bodies will be
required to carry session information (Session Description Protocol -
SDP) in addition to ISUP and/or billing information.
PSTN interworking nodes MUST understand the MIME type of
"multipart/mixed" as defined in RFC2046 [4]. Clients express support
for this by including "multipart/mixed" in an "Accept" header.
rfc3261
http://www.faqs.org/rfcs/rfc3261.htmlДокументы по ITU-T:
•Q.GTD.1 —Generic Transparency Descriptor Syntax Definition
•Q.GTD.2 —Generic Transparency Descriptor Usage Rules and Mappings
Интересная информация тут:
http://docstore.mik.ua/univercd/cc/td/doc/...t.htm#wp1103885Документы от Cisco:
http://www.cisco.com/en/US/docs/voice_ip_c...4_1_/FMsipt.pdfhttp://old.ciscoexpo.ru/moscow/2008/downlo...te-afelizha.pdfИз пакета видно, что формируется multipart/mixed
который содержит в себе информацию, после которой есть мнения что станция валится в ребут:
Content-Type: multipart/mixed;boundary=unique-boundary-1
MIME-Version: 1.0
Content-Length: 414
--unique-boundary-1
Content-Type: application/sdp
v=0
o=personeta 23927 52451 IN IP4 213.87.52.254
s=iPECSMG Call
c=IN IP4 213.87.52.254
t=0 0
m=audio 19638 RTP/AVP 8 101
a=rtpmap:8 PCMA/8000
a=rtpmap:101 telephone-event/8000
a=fmtp:101 0-15
a=ptime:20
--unique-boundary-1
Content-Type: application/gtd
Content-Disposition: signal; handling=optional
ANM,
CNN,00,,0,4,
--unique-boundary-1---ÀjOtÅ^@^@N^B^@^@N^B^@^@^@&Z^EãÇ´^Nܲ^G/^H^@EÀ^B@<8c>0^@^@@^A%<94>¬^P^OÓÕW4þ^C^C^?æ^@^@^@^@E^@^D^_^@^@^@^@t^Q|<95>ÕW4þ¬^P^OÓ^SÄ^SÄ^D^KVÎSIP/2.0 200 OK