Source note · Firewall ports and IP ranges for cloud calling
A Webex Calling endpoint must use the _sips._tcp service and protocol combination as the prefix for the DNS SRV lookup that obtains the host address for TLS-based communication, must honour the host port weight and priority advertised for each host address, and must create an affinity of host to port when opening the socket for SIP registration, with selection by priority and weight following RFC 2782.
Checked 2026-09-16
- Vendor
- Cisco
- Product
- Webex Calling
- Subsystem
- signalling
- Deployment
- not restricted
- Region
- not restricted
- Release range
- not restricted
- Checked
- 2026-09-16
Sources
- Security requirements for Webex Calling — Cisco Systems, Inc. (help.webex.com) · tier 2 current vendor documentation · Requirements for endpoints, Resolution of host address from the DNS SRV address
Cite this note
APA
WarmTransfer. (2026, September 16). Firewall ports and IP ranges for cloud calling: source note fwports-sips-tcp-srv-and-host-affinity. WarmTransfer. https://warmtransfer.net/knowledge/claims/fwports-sips-tcp-srv-and-host-affinity
BibTeX
@misc{warmtransfer-claim-fwports-sips-tcp-srv-and-host-affinity,
title = {Firewall ports and IP ranges for cloud calling: source note fwports-sips-tcp-srv-and-host-affinity},
author = {{WarmTransfer}},
year = {2026},
url = {https://warmtransfer.net/knowledge/claims/fwports-sips-tcp-srv-and-host-affinity},
note = {Source note fwports-sips-tcp-srv-and-host-affinity, checked 2026-09-16}
}