Secure Real-Time Protocol Implementation Considerations for Cisco Unified CM and SIP Gateway

Implementing Secure Real-Time Protocol

Prev Question Next Question


A collaboration engineer has been asked to implement secure real-time protocol between a Cisco Unified CM and its SIP gateway.

Which option is a consideration for this implementation?



Click on the arrows to vote for the correct answer

A. B. C. D.


The correct answer is D: SRTP is supported only in Cisco IOS 15.x and higher.

Secure Real-Time Protocol (SRTP) is a protocol used to provide confidentiality, integrity, and authentication for real-time media streams such as voice and video. It is used in VoIP systems to protect the privacy and security of communications.

When implementing SRTP between a Cisco Unified CM and its SIP gateway, it's important to consider the compatibility of the devices involved. Specifically, the version of the Cisco IOS running on the SIP gateway must be 15.x or higher in order to support SRTP. If the IOS version is lower than 15.x, then SRTP will not be available and another solution must be found.

Option A is incorrect because T.38 and Cisco fax protocol are not relevant to the implementation of SRTP between a Cisco Unified CM and its SIP gateway.

Option B is incorrect because there is no requirement for SIP to use GMT time. SIP uses the Session Description Protocol (SDP) to negotiate the parameters of a call, including the time zone, and can support any time zone.

Option C is incorrect because Call hold RE-INVITE is a feature that allows a call on hold to be resumed without the need for a full renegotiation of the call parameters. This feature is supported in SIP and should not be a consideration when implementing SRTP.