Source note · Expressway business-to-business calling

If the target domain publishes no NAPTR records, the Expressway uses a default list of _sips._tcp, _sip._tcp and _sip._udp SRV queries for that domain.

Checked 2026-09-25

Vendor: Cisco
Product: Cisco Expressway
Subsystem: DNS zone
Deployment: on-premises
Region: not restricted
Release range: X15.0 to X15.2 (seen in snippet); X15.4 not confirmed
Checked: 2026-09-25

Sources

Cisco Expressway Administrator Guide (X15.2) - Dial Plan and Call Processing — Cisco Systems · tier 2 current vendor documentation · URI Resolution Process Using DNS (SIP)

Cite this note

APA

WarmTransfer. (2026, September 25). Expressway business-to-business calling: source note expressway-b2b-calling-default-srv-list-no-naptr. WarmTransfer. https://warmtransfer.net/knowledge/claims/expressway-b2b-calling-default-srv-list-no-naptr

BibTeX

@misc{warmtransfer-claim-expressway-b2b-calling-default-srv-list-no-naptr,
  title  = {Expressway business-to-business calling: source note expressway-b2b-calling-default-srv-list-no-naptr},
  author = {{WarmTransfer}},
  year   = {2026},
  url    = {https://warmtransfer.net/knowledge/claims/expressway-b2b-calling-default-srv-list-no-naptr},
  note   = {Source note expressway-b2b-calling-default-srv-list-no-naptr, checked 2026-09-25}
}

Read in context