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What is SRTP Cisco?

What is SRTP Cisco?

SRTP is an extension of the Real-time Transport Protocol (RTP) Audio/Video Profile (AVP) and ensures the integrity of RTP and Real-Time Control Protocol (RTCP) packets that provide authentication, encryption, and the integrity of media packets between SIP endpoints.

What is SRTP fallback?

The SIP SRTP Fallback to Nonsecure RTP feature enables a Cisco IOS Session Initiation Protocol (SIP) gateway to fall back from Secure Real-time Transport Protocol (SRTP) to Real-time Transport Protocol (RTP) by accepting or sending an RTP/Audio-Video Profile(AVP) (RTP) profile in response to an RTP/SAVP (SRTP) profile.

What is SRTP in SIP?

SRTP is an RTP profile intended to provide encryption, message authentication and integrity, and relay attach protection to the RTP data. SIP TLS protocol aims primarily to provide privacy and data integrity between two or more communicating computer applications.

How do I configure SRTP?

Enable SRTP in the SIP Profile The procedure below describes this configuration. Right click on the SIP Profiles object and select New SIP Profile. In the Name field enter a name that identifies this SIP profile. In the SRTP Mode field select whether SRTP will disabled, Mandatory, or RTP fallback as displayed below.

What is the difference between SRTP and RTP?

RTP is suitable for video-streaming application, telephony over IP like Skype and conference technologies. The secure version of RTP, SRTP, is used by WebRTC, and uses encryption and authentication to minimize the risk of denial-of-service attacks and security breaches.


SRTP is not a transport, it is simply the encryption of the RTP to secure it, hence the S before RTP. The RTP is still transported in UDP but both parties to the call have exchanged keys in the SIP to enable encryption. You can use SRTP regardless of the transport used for the SIP as they are unrelated.

How do I enable SRTP in Cucm?

Find the gateway or trunk, as described in the Unified Communications Manager. After you open the configuration window for the gateway/trunk, check the SRTP Allowed check box.

What is cube license?

CUBE licensing is, in all cases, a per-session license, where a “session” is defined as a two-way call transiting CUBE, either for signaling, media or both, regardless of the number of media sessions involved in that call. There are two versions of the CUBE Legacy licensing, Standard and Redundant.


SIP clients typically use TCP or UDP on port numbers 5060 or 5061 for SIP traffic to servers and other endpoints. Port 5060 is commonly used for non-encrypted signaling traffic whereas port 5061 is typically used for traffic encrypted with Transport Layer Security (TLS).

What is the difference between SIP and sips?

SIPS, which stands for SIP Secure, is SIP, extended with TLS (Transport Layer Security). With this TLS, a secure connection between IP PBX and VoIP telephone can be established using a handshake approach. To use those secure protocols, all involved devices have to support SIPS and SRTP.

Does SRTP use TCP or UDP?


Protocol suite: TCP/IP.
Port: 5004 (UDP).
Working groups:
Working groups: avt, Audio/Video Transport.

What is the purpose of SRTP?

The Secure Real-time Transport Protocol (SRTP) is a security framework that extends the Real-time Transport Protocol (RTP) and allows a suite of crypto mechanisms. WebRTC uses DTLS-SRTP to add encryption, message authentication and integrity, and replay attack protection.

When to enable SRTP in Cisco Unified border element?

From Cisco IOS XE Everest Release 16.5.1b onwards, when SRTP is enabled, by default Cisco Unified Border Element supports secure calls between networks using different cipher suites. The cipher suites supported for SRTP-SRTP interworking with default preference order is as follows: Figure 1. SRTP-SRTP Interworking

Are there any Cisco applications that do not support SRTP?

RTP Cisco applications or servers. For example, Cisco Unified MeetingPlace, Cisco WebEx, or Cisco Unity, which do not support SRTP, or have not been configured for SRTP, or are resident in a secure data center, as shown in the figure below. RTP to third-party equipment.

Is there impact on SRTP-SRTP pass-through calls?

There is no impact on SRTP-SRTP pass-through calls. SRTP is configured on one dial peer using the srtp and srtp fallback commands. RTP is configured on the other dial peer. The dial peer configuration takes precedence over the global configuration on the CUBE. Fallback handling occurs if one of the call endpoints does not support SRTP.

How to enable SRTP in global VoIP SIP?

voice-class sip srtp negotiate cisco (Enable this CLI along with srtp fallback command to support SRTP fallback with Cisco Unified Communications Manager ) In global VoIP SIP configuration mode srtp fallback (for interworking with devices other than Cisco Unified Communications Manager)