When web app authentication fails during SIP Gateway sign-in, Microsoft says to confirm the credentials by signing in to the Teams app with them and, if Conditional Access is used, to make sure the SIP Gateway IP addresses are excluded.
Checked 2026-10-02
- Vendor
- Microsoft
- Product
- Microsoft Teams SIP Gateway
- Subsystem
- authentication
- Deployment
- multi-tenant
- Region
- not restricted
- Release range
- current as of 2026-10-02
- Checked
- 2026-10-02
Sources
- Common Issues When Using SIP Devices With Teams — Microsoft · tier 2 current vendor documentation · Common Issues When Using SIP Devices With Teams > Web app authentication fails when I try to sign in
Cite this note
APA
WarmTransfer. (2026, October 2). Troubleshooting phones signing in through Teams SIP Gateway: source note teams-sip-gateway-troubleshooting-web-auth-fail-checks. WarmTransfer. https://warmtransfer.net/knowledge/claims/teams-sip-gateway-troubleshooting-web-auth-fail-checks
BibTeX
@misc{warmtransfer-claim-teams-sip-gateway-troubleshooting-web-auth-fail-checks,
title = {Troubleshooting phones signing in through Teams SIP Gateway: source note teams-sip-gateway-troubleshooting-web-auth-fail-checks},
author = {{WarmTransfer}},
year = {2026},
url = {https://warmtransfer.net/knowledge/claims/teams-sip-gateway-troubleshooting-web-auth-fail-checks},
note = {Source note teams-sip-gateway-troubleshooting-web-auth-fail-checks, checked 2026-10-02}
}