Datasheet

[e-mail]. Properly planning how the company will set SIP URIs for each client will
prove useful in later stages of a Live Communications Server deployment and for future use of Microsoft
Unified Communications products.
SIP Methods
Session Initiation Protocol uses its own methods to communicate SIP messages between SIP clients and
SIP servers. Similar to other Internet protocols, SIP provides a messaging structure. SIP messages include
the following methods:
❑ INVITE
❑ ACK
❑ BYE
❑ CANCEL
❑ OPTIONS
❑ REGISTER
❑ SUBSCRIBE
❑ NOTIFY
❑ MESSAGE
❑ INFO
❑ SERVICE
❑ NEGOTIATE
❑ REFER
Each SIP message request requires a method, a SIP URI, and the version of SIP that the message request
is using. The following table describes briefly each SIP method.
SIP Method Method Description
ACK The ACK and INVITE message are synonymous in that they are sent together by
an initiating client. The
ACK method verifies that the session has been initiated.
BYE The BYE method terminates the SIP session. This method would be used by a con-
tact t
hat has finished its session with another contact and is ready to exit the session.
CANCEL A CANCEL method is used by a client that may have a pending message request
that it wants to cancel, terminating the request, but not the session. This would
be used if a contact wanted to initiate a collaboration sharing session with
another contact and then decided to cancel the request, although both contacts
could continue other messaging requests such as Instant Messaging each other.
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