Extracting SDP Parameters with Kamailio
Robust Header Compression (ROHC) and it’s use for compressing RTP / VoLTE traffic headers.
SDPs ptime values, what it means, how it can go wrong and how to fix it.
Load testing a standard VM to see how many RTPengine transcoding sessions it can manage concurrently
Connecting to RTPengine via Python
Using Kamailio to route traffic to the nearest geographical RTPengine instance for lowest latency/best experience.
Basic usage of a Python RTP library I wrote
Using RTPengine and Kamailio to transcode
Using rtpengine to bridge calls in Kamailio
Workhorse of VoIP / VoLTE / SIP / H.323 / IMS, we take a deep dive into what every bit of RTP means. Pun very much intended.
Understanding the SDP protocol and how it’s used to negotiate and setup media sessions.
DTMF’s implementation in VoIP and the 3 types of DTMF encoding (Inband, RTP Event and SIP INFO)
RFC2833 was designed to carry DTMF signalling, other tone signals and telephony events in RTP packets. This was later superseded by RFC4733, but everyone still referrers to this protocol as RFC2833, so I will too. RFC2833 a special RTP payload designed to carry DTMF signalling information, so it operates on the same source / destination […]