As voice traffic traverses Twilio the media will enter and exit Twilio's infrastructure at one of our media edges. The edge(s) present will depend on the call type. Each edge will have an inbound and outbound stream representing what was received at and sent from the edge in question.
With this in mind it's important to understand when you are looking at, for example, the outbound stream being passed to your SIP infrastructure on a SIP domain call the source of that stream is the inbound stream received on the carrier edge on the parent or child call.
Voice SDK Calls
Media Edge
Description
sdk_edge
The media stream received at the SDK sensors from the Twilio Voice SDK media gateway and events generated by the SDK based on the condition of the media stream.
client_edge
Inbound: the media stream received at the Twilio Voice SDK media gateway from the SDK. Outbound: the stream sent to the SDK from the parent/child call or conference.
SIP Trunking Calls
Media Edge
Description
sip_edge
Inbound: the media stream received at the Twilio Public media gateway from your SIP infrastructure. Outbound: the media stream sent to your SIP infrastructure from the Twilio Public media gateway.
carrier_edge
Inbound: the media stream received at the Twilio Carrier media gateway from the PSTN. Outbound: the media stream sent to the PSTN from the Twilio Carrier media gateway.
SIP Interface Calls
Media Edge
Description
sip_edge
Inbound: the media stream received at the Twilio Public media gateway from your SIP infrastructure. Outbound: the media stream sent to your SIP infrastructure from the Twilio Public media gateway.
PSTN Calls
Media Edge
Description
carrier_edge
Inbound: the media stream received at the Twilio Carrier media gateway from the PSTN. Outbound: the media stream sent to the PSTN from the Twilio Carrier media gateway.
