Posts in technical.
VoIP certificate expiration causes silent registration failures, one-way audio, and stalled provisioning. Where certs hide, how they fail, and what to do.
IPv6 now carries half of Google's traffic, yet VoIP remains stubbornly IPv4. Why SIP resists the transition, where dual-stack breaks calls, and what to test.
RTCP runs alongside every RTP stream, reporting packet loss, jitter, and round-trip time. What sender and receiver reports contain, and where the data goes.
A session border controller sits between your phone system and the internet. What SBCs actually do, how they differ from SIP ALG, and who really needs one.
SIP ALG rewrites VoIP signaling as it crosses your router and almost always makes things worse. How to check if it is enabled and what to do instead.
How T.38 fax relay works, how it differs from fax passthrough, the SIP re-INVITE flow that sets it up, and why T.38 still breaks so often in production.
Using Wireshark and packet captures for VoIP troubleshooting: where to capture, what to look for in SIP and RTP streams, and connecting packets to symptoms.
Wi-Fi introduces real problems for VoIP calls. A practical breakdown of when wireless works, when it fails, and how to fix it.