In Part 1 of our SIP primer, I covered the SIP foundation layers starting from the message structure and ending with the SIP transactions. We saw how phone registrations and proxies could work using ...

SIP session requests leverage the “session description protocol (SDP)” to define session characteristics such as media type, codec, and so on. While the IETF and SIPforum have standardized many of the ...

Update: We're in the last throes of winter break 2019, which means most Ars' home office phones can stay dormant for a few more days. As such, we've been resurfacing a few classics from the ...

The 18th Internet Telephony Conference & Expo (ITEXPO) came to Los Angeles last week, and being the opportunistic sort, I decided to get myself on the press list. That's one of the advantages of ...

Codec manufacturer APT announced that its IP codecs — the Horizon, Meridian, Eclipse and Oslo lines —support SIP/SDP protocols. This will allow APT’s IP codecs to communicate with codecs made by other ...