Cisco Unified Border Element Configuration Guide - Cisco IOS XE 17.6 Onwards - SRTP-SRTP Interworking

Publisher

Cisco Systems

URL

https://www.cisco.com/c/en/us/td/docs/ios-xml/ios/voice/cube/ios-xe/config/ios-xe-book/cube_m_srtp-srtp-interworking.html

Published

2026-04-25

Updated

unknown

Accessed

2026-09-23

HTTP status

200

License

Cisco website terms of use; no-redistribution; short excerpts and locators only

Source notes citing this source

• SRTP is enabled on a dial-peer with srtp (optionally srtp fallback), and cipher-suite preference is set with voice class srtp-crypto tag containing crypto 1-4 entries, applied with voice-class sip srtp-crypto tag. in context
• Any call flow that switches from RTP to SRTP on the same SIP call leg requires the supplementary-service media-renegotiate command to ensure two-way audio. in context
• CUBE does not support asymmetric SRTP fallback configuration or SRTCP-RTCP interworking, and supports SRTP-SRTP calls with transcoding only from IOS XE Bengaluru 17.6.1a. in context
• CUBE supports the SRTP cipher suites AEAD_AES_256_GCM, AEAD_AES_128_GCM, AES_CM_128_HMAC_SHA1_80 and AES_CM_128_HMAC_SHA1_32, in that default preference order. in context
• show sip-ua calls displays the local and remote crypto keys, crypto suites and media stream details for SRTP calls. in context
• CUBE's default SRTP crypto-suite preference, highest first, is AEAD_AES_256_GCM, AEAD_AES_128_GCM, AES_CM_128_HMAC_SHA1_80, AES_CM_128_HMAC_SHA1_32. in context
• CUBE SRTP-SRTP interworking, which lets the two call legs use different crypto suites, was first supported in Cisco IOS XE Everest 16.5.1b. in context
• CUBE SRTP-SRTP interworking does not support SRTCP-RTCP interworking, asymmetric SRTP fallback, GCM ciphers with RTP header extensions, or more than one audio or video m-line. in context
• On CUBE, voice class srtp-crypto sets a crypto preference list numbered 1 to 4, with 1 highest. It can be applied globally, to a voice class tenant, or per dial-peer with voice-class sip srtp-crypto. in context
• CUBE's SRTP fallback option lets a call revert to RTP when the far end does not support SRTP, which Cisco positions as needed for non-secure supplementary services such as music on hold and call transfer. in context

Cite this source record

APA

WarmTransfer. (2026, April 25). Cisco Unified Border Element Configuration Guide - Cisco IOS XE 17.6 Onwards - SRTP-SRTP Interworking. WarmTransfer. https://warmtransfer.net/knowledge/sources/cisco-cube-xe-srtp-srtp-interworking

BibTeX

@misc{warmtransfer-cisco-cube-xe-srtp-srtp-interworking,
  title  = {Cisco Unified Border Element Configuration Guide - Cisco IOS XE 17.6 Onwards - SRTP-SRTP Interworking},
  author = {{WarmTransfer}},
  year   = {2026},
  url    = {https://warmtransfer.net/knowledge/sources/cisco-cube-xe-srtp-srtp-interworking},
  note   = {Cisco Systems, accessed 2026-09-23}
}