HP-UX C SIP Stack Programmer's Guide (Novembery 2007)

SIP Stack 23
Feature Support
METHODS The SIP Stack supports baseline SIP methods, such as INVITE, ACK, BYE,
CANCEL, OPTIONS and REGISTER. In addition, the SIP Stack supports
extension methods, such as REFER, NOTIFY, SUBSCRIBE, PRACK,
MESSAGE, UPDATE, INFO and others.
RESPONSES The SIP Stack supports all response code classes (1xx to 6xx) specified in
RFC 3261.
NEW MESSAGE
PARAMETERS
The SIP Stack can accept and encode new non-standard message fields which
do not appear in the baseline specification, such as methods, response codes,
headers and header parameters.
SECURITY The SIP Stack can authenticate any SIP request using the Digest authentication
scheme in conformity with the SIP specification. Both Client authentication and
Server authentication are supported. The SIP Stack also supports the TLS
Transport layer which provides message encryption.
MULTIPART MIME
BODIES
Multipart MIME is a generic mechanism that allows the encapsulation and
transfer of arbitrary chunks of data, both text and binary, within text messages.
Today, Multipart MIME is used successfully in e-mail and the web. The SIP
specification allows the usage of Multipart MIME as message bodies. Multipart
MIME is a necessary capability for some features, such as ISUP message
tunneling through SIP, which is part of SIP-T. Multipart MIME is also useful for
other purposes, such as sending thumbnail pictures of the caller inside of
INVITE messages.
ADVANCED DNS
Q
UERIES
RFC 3263 (Locating SIP Servers) defines procedures for using advanced SRV
and NAPTR DNS queries to determine the transport protocol, IP address and
port at which a specific SIP server is available. These procedures can be used to
dynamically update server locations and to implement redundancy among
servers for fault tolerance or load balancing.
FEATURE SUPPORT The SIP Stack includes a set of IETF extensions that are of high importance, and
that are otherwise difficult to implement.
SUBSCRIBE-
NOTIFY (SIP E
VENTS)
RFC 3265 (SIP Specific Event Notification) is a SIP extension that allows for
subscription and event notifications using SIP. SIP Events is an important
infrastructure for services such as Presence and Message Waiting Indication.