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Signaling, JSEP, and the media plane

WebRTC names a browser protocol suite. JSEP leaves the signaling protocol to the application. SIP over WebSocket is one such protocol.

Learn in 5 minutes

  1. Separate the browser media stack from the signaling protocol
  2. Say what RFC 8825 and RFC 8829 each are
  3. Name RFC 7118 as SIP on a WebSocket, not a new SIP method

Visual

The application picks SIP. The socket is only the transport. · study drawing · cyphermonkeylabs.com PageWSS server GET 101 REGISTER 200

SVG HTML PNG

The application chooses signaling. The browser still has to carry media the WebRTC suite names.

Worked example

Name the document Step the ladder. The first hop is an HTTP handshake. The third hop is SIP.

  1. Press Step until the handshake is selected.
  2. Read the subprotocol token.
  3. Step to REGISTER and name the method.

Fault

A trace shows HTTP 101 and then no Via header. The debugger is waiting for a SIP 100 Trying on the GET.

RFC 6455 is the handshake. RFC 7118 carries SIP after the subprotocol is selected.

Quiz

RFC 8825 is


JSEP leaves the signaling protocol to


RFC 7118 defines


RFC 6455 is


A browser softphone that sends INVITE over WebSocket has changed


The session description is what JSEP expects the application to exchange because


Ecosystem

Glossary, sister systems, and the integration seam for this room.

Workforce management WFM forecasts volume and builds schedules. It consumes contact-center events. It does not parse Via headers. When a forecast is wrong, the SIP symptom is usually queue delay and 480 or carrier congestion, not a broken dialog ID.

Glossary · Ecosystem map · Ports · Troubleshooting

Sources and go deeper