Webex Calling ICE media path optimization

See also

Sources

1. 1
   The word TURN occurs 0 times in the Webex Calling port reference article and 0 times in the Webex Calling media optimization article, so no Cisco source the corpus holds names a relay candidate or a TURN server for Webex Calling even though both describe a media relay in the cloud that ICE removes.field report

   Port Reference Information for Webex Calling · whole article, and the Webex Calling media optimization article, counted against the rendered text · Checked 2026-09-16
2. 2
   In Cisco's worked example of a call between 2 phones in Australia for a customer assigned to the United States region, the media path is kept on the access session border controllers in the Australia region under the control of the United States instance while the SIP signalling for the call goes back to the call control entity in the United States region, and Cisco describes that regional media path as the fallback that ICE optimization can replace with a direct path.

   Cisco Preferred Architecture for Webex Calling — Design Overview · Architectural Overview, Figure 3 Regional Access SBCs, worked example · Checked 2026-09-16
3. 3
   Data for optimized calls is available through the Media Quality analytics page in Control Hub or through the Control Hub troubleshooting tool.

   Webex Calling media optimization with Interactive Connectivity Establishment (ICE) · Analytics for media optimization · Checked 2026-09-16
4. 4
   The Webex Calling media optimization article names no edition restriction and does not mention Webex for Government, so the corpus holds no source for the claim that media optimization is unavailable in that edition.field report

   Webex Calling media optimization with Interactive Connectivity Establishment (ICE) · whole rendered article, 4260 characters, searched for government and for edition · Checked 2026-09-16
5. 5
   Cisco states that browsers use an ephemeral source port for Webex Calling media that can be controlled by setting the WebRtcUdpPortRange policy in a mobile device management profile, and that the Webex Calling service behaves normally if no such service is set.

   Port Reference Information for Webex Calling · IP Subnets for Webex Calling Services, WebRTC row · Checked 2026-09-16
6. 6
   Outbound SRTP media from Local Gateways devices and Webex App clients to the Webex Calling cloud uses destination ports 5004, 9000, 8500 to 8699 and 19560 to 65535 over UDP, and media from Webex Calling to a certificate-based Local Gateway uses 19560 to 65535.

   Port Reference Information for Webex Calling · IP Subnets for Webex Calling Services, Call media to Webex Calling destination ports · Checked 2026-09-16
7. 7
   Cisco states that where STUN and ICE negotiation succeeds for a call within the organisation the media relay in the cloud is removed from the communication path and media flows directly between the apps and devices, with the Webex App sending directly on 8500 to 8699 and devices sending directly to one another on 19560 to 19661.

   Port Reference Information for Webex Calling · IP Subnets for Webex Calling Services, Call media to Webex Calling row · Checked 2026-09-16
8. 8
   Webex Calling media optimization runs in 4 phases: candidate discovery in which an endpoint collects its local address and a server reflexive address obtained by querying a STUN server in the Webex Calling cloud, candidate exchange in which endpoints exchange those addresses using SIP, connectivity checks in which the endpoints test the exchanged candidates, and media path optimization in which a re-INVITE moves the media onto the chosen path.

   Webex Calling media optimization with Interactive Connectivity Establishment (ICE) · Phases of Webex Calling media optimization · Checked 2026-09-16
9. 9
   Media optimization with a Local Gateway requires network reachability between the device and the Local Gateway, achieved either by assigning a public IP address to the Local Gateway or by ensuring the Local Gateway host address is accessible to a device on the same network as the gateway.

   Webex Calling media optimization with Interactive Connectivity Establishment (ICE) · Prerequisites and limitations, reachability bullets · Checked 2026-09-16
10. 10
    Media optimization on a Local Gateway is enabled with the command STUN usage lite, the Local Gateway running Cisco Unified Border Element supports ICE-lite with several restrictions, and the feature requires a minimum CUBE software version of 17.3 or 16.12.5.

    Webex Calling media optimization with Interactive Connectivity Establishment (ICE) · Prerequisites and limitations, Local Gateway paragraphs · Checked 2026-09-16
11. 11
    Cisco states that UDP is its preferred transport protocol for Webex Calling media and recommends using only SRTP over UDP, and that TCP and TLS as transport protocols for media are not supported for Webex Calling in production environments because their connection-oriented nature affects media quality over network loss.

    Port Reference Information for Webex Calling · Firewall configuration, transport protocol paragraph · Checked 2026-09-16
12. 12
    Cisco states that Webex Calling devices sharing a public address through NAT or PAT may use the same SIP signalling source port within the 5060 to 5280 range, that the NAT device must be able to translate overlapping source ports to unique translated ports, and that strict source-port preservation configurations can cause device registration failures.

    Port Reference Information for Webex Calling · Firewall configuration, NAT pool sizing paragraph · Checked 2026-09-16
13. 13
    Cisco instructs administrators to validate the NAT pool size required for app and device connectivity and to assign adequate public addresses to prevent port exhaustion, stating that port exhaustion contributes to internal users and devices being unable to connect to the Webex Calling and Webex Aware services.

    Port Reference Information for Webex Calling · Firewall configuration, NAT pool sizing paragraph · Checked 2026-09-16
14. 14
    Cisco states that Cisco phones send a follow-up REGISTER refresh every 1 to 2 minutes and that a network implementing NAT or stateful packet inspection should set a connection timeout of at least 30 minutes, which it says allows reliable connectivity while reducing the battery consumption of mobile devices.

    Port Reference Information for Webex Calling · Firewall configuration, NAT timeout paragraph · Checked 2026-09-16
15. 15
    Cisco states that for network topologies using firewalls within a customer premise the administrator must allow the media source and destination port ranges inside the network for the media to flow, and gives the Webex App example of allowing audio 8500 to 8599 and video 8600 to 8699 as both source and destination.

    Port Reference Information for Webex Calling · IP Subnets for Webex Calling Services, Call media to Webex Calling row · Checked 2026-09-16
16. 16
    Where call recording is enabled the media for recorded calls is routed to the cloud and is not optimized, and Cisco states that media optimization and call recording each independently introduce a small audio delay at the beginning of a call and that together the delay is slightly longer and more noticeable to customers.

    Webex Calling media optimization with Interactive Connectivity Establishment (ICE) · Prerequisites and limitations, call recording paragraphs · Checked 2026-09-16
17. 17
    The Webex Calling media source port ranges differ by device class: devices use 19560 to 19661, Room Series devices use 52050 to 52099 for audio and 52200 to 52299 for video, VG400 analog telephone adapters use 19560 to 19849, and the Webex App uses 8500 to 8599 for audio and 8600 to 8699 for video.

    Port Reference Information for Webex Calling · IP Subnets for Webex Calling Services, device rows read as cells · Checked 2026-09-16
18. 18
    Webex Calling media optimization is supported across desk phones excluding DECT and analog telephone adapter devices, the Webex App, and the Local Gateway solution, and is enabled by default on desk phones and the Webex App without configuration.

    Webex Calling media optimization with Interactive Connectivity Establishment (ICE) · Prerequisites and limitations, first 3 paragraphs · Checked 2026-09-16
19. 19
    Signalling data is always sent to the Webex Calling cloud to route calls and an active internet connection is always required to make Webex Calling calls; media optimization changes only the media path, which Cisco notes makes up most of a call's traffic.

    Webex Calling media optimization with Interactive Connectivity Establishment (ICE) · Prerequisites and limitations, routing paragraph · Checked 2026-09-16
20. 20
    Cisco states that calls can only be optimized within a single organisation and that for interorganization calls media must flow through the PSTN for regulatory reasons.

    Webex Calling media optimization with Interactive Connectivity Establishment (ICE) · Prerequisites and limitations, organisation paragraph · Checked 2026-09-16
21. 21
    Cisco recommends turning off the SIP Application Layer Gateway or similar function on any SIP aware router or firewall, stating that although all Webex Calling traffic is encrypted certain SIP ALG implementations can cause issues with firewall traversal.

    Port Reference Information for Webex Calling · SIP Application Layer Gateway · Checked 2026-09-16
22. 22
    The Webex Calling port reference revision history records that on 7 September 2026 the phone's source port range was expanded from 5060 to 5080 into 5060 to 5280 to accommodate an updated Cisco feature enabling support for up to 130 lines.

    Port Reference Information for Webex Calling · Document revision history, 7 September 2026 entry · Checked 2026-09-16

Documents

Cite this page

WarmTransfer. (2026, September 16). Webex Calling ICE media path optimization. WarmTransfer. https://warmtransfer.net/knowledge/webex-calling-media-optimization

@misc{warmtransfer-webex-calling-media-optimization,
  title  = {Webex Calling ICE media path optimization},
  author = {{WarmTransfer}},
  year   = {2026},
  url    = {https://warmtransfer.net/knowledge/webex-calling-media-optimization},
  note   = {Verified 2026-09-16}
}