Source note · SIP scanning and telephony denial of service
Because Direct Routing signaling comes only from published Microsoft ranges over TLS, a Direct Routing SBC can drop inbound SIP on the Teams-facing interface from any other source; the Microsoft page does not itself frame this as scanner protection.
inferred · Checked 2026-09-25
- Vendor
- Microsoft
- Product
- Teams Phone Direct Routing
- Subsystem
- SIP signaling - firewall
- Deployment
- multi-tenant
- Region
- not restricted
- Release range
- current as of 2026-09-25
- Status
- inferred
- Checked
- 2026-09-25
Sources
- Plan Direct Routing — Microsoft (Microsoft Learn) · tier 2 current vendor documentation · SIP signaling: FQDNs; SIP signaling ports
Cite this note
APA
WarmTransfer. (2026, September 25). SIP scanning and telephony denial of service: source note sip-scanning-tdos-inference-dr-source-allowlist. WarmTransfer. https://warmtransfer.net/knowledge/claims/sip-scanning-tdos-inference-dr-source-allowlist
BibTeX
@misc{warmtransfer-claim-sip-scanning-tdos-inference-dr-source-allowlist,
title = {SIP scanning and telephony denial of service: source note sip-scanning-tdos-inference-dr-source-allowlist},
author = {{WarmTransfer}},
year = {2026},
url = {https://warmtransfer.net/knowledge/claims/sip-scanning-tdos-inference-dr-source-allowlist},
note = {Source note sip-scanning-tdos-inference-dr-source-allowlist, checked 2026-09-25}
}