Table Of Contents

SIP Compliance and Interoperability

SIP Features and SBC Compliance

SIP Compliance and Interoperability

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This appendix lists examples of Session Initiation Protocol (SIP) services and features and the type of support provided by Cisco Unified Border Element (SP Edition).

SIP Features and SBC Compliance

The following table lists some examples of SIP services and features and extent of interoperability and compliance provided by Cisco Unified Border Element (SP Edition) on the unified model.

Many of the SIP services or features in the table are listed in the draft-ietf-sipping-service-examples.txt specification.

The table covers most features offered in what are considered IP Centrex offerings from local exchange carriers and PBX (Private Branch Exchange) features. The table also includes services involving some extensions to SIP, including the REFER, SUBSCRIBE, and NOTIFY methods and the Replaces and Join headers.

Table 1 SBC Compliance and Support of SIP Services and Features 

SIP Service or Feature	Cisco Unified Border Element (SP Edition) Compliance or Support
Call Hold	Supported.
Consultation Hold	Supported.
Music on Hold	Supported.
Call Hold with Music on Hold	Supported.
Find-Me	Passthrough only. SBC does not perform find-me function.
Call Park	Passthrough only. SBC does not perform call park function.
Call Forking	Supported.
Caller-ID	Passthrough only. SBC does not perform caller-ID function.
Calling Name Delivery	Passthrough only. SBC does not perform calling name delivery function.
Click to Dial	Partial (not supported with SBC between end user computer and phone).
Message Waiting Indicator	Passthrough, depending on SIP SUBSCRIBER/NOTIFY messages
Call Forwarding - Busy	Partial (not supported with SBC between proxy and callee).
Call Forwarding - No Answer	Partial (not supported with SBC between proxy and callee).
Call Forwarding - Unconditional	Supported.
SIP Session Refreshment with re-INVITE
SIP - Specific Event Notification	Partial support (RFC 3265).
Transfer - Unattended	Supported.
Transfer - Attended	Supported.
Transfer - Instant Messaging	Supported.
3-way Conference - Third Party is Added	Not supported.
3-way Conference - Third Party Joins	Not supported.
Single Line Extension	Not supported.
Call Management (Incoming Call Screening)	Passthrough only. SBC does not perform Call Screening function.
Call Management (Outgoing Call Screening)	Passthrough only. SBC does not perform Call Screening function.
Call Pickup	Not supported.
Automatic Redial	Not supported.