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REGISTER and bindings

REGISTER binds an address-of-record to one or more Contacts, and the registrar is a different role from the proxy.

Learn in 5 minutes

  1. Point To at the address-of-record and Contact at the binding
  2. Refresh with the same Call-ID and a higher CSeq
  3. Handle 423 by raising the expiry to Min-Expires

Visual

Challenge, then a binding · study drawing · cyphermonkeylabs.com UARegistrar REGISTER 401 REGISTER 200

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The 200 OK lists the bindings the registrar is holding after the request.

Worked example

Read the 423 The registrar rejected the interval. The header you need is Min-Expires.

  1. Dissect the 423.
  2. Read Min-Expires.
  3. Decide the next Expires value.

Fault

A phone sends BYE to the registrar to clear a binding. The registrar answers 481 and the Contact remains.

Registration is not a dialog. There is nothing for BYE to terminate.

Quiz

The address-of-record on REGISTER is


A registrar is


423 Interval Too Brief includes


Removing every binding uses


A higher Contact q value


REGISTER is refreshed by


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