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Voice, EF, and what the PHB does not design
RFC 3246 defines the EF PHB. RFC 4594 maps telephony to EF. This lesson does not design a LAN.
Learn in 5 minutes
- Name EF as the PHB for the telephony class
- Keep the recommended codepoint inside the RFC
- Leave switch queues and campus design out of the lesson
Visual
Voice media follows the telephony mapping. Signaling is a different service class in RFC 4594, and this table does not assign it a codepoint.
Worked example
Where EF applies Which hop's SDP names the media that the telephony class covers?
- Press Play.
- Step until the hop named in the question.
- Inspect that message and answer the check.
Vendor menus, ports, and license names change. Confirm before relying on a sentence that is not an RFC.
Fault
One-way audio is blamed on SIP, and the ticket adds a campus queue map that no design review approved. The 200 OK SDP says c=IN IP4 203.0.113.20 and m=audio 19642 RTP/AVP 0.
The SDP names the media. The PHB is EF. The queue map was invented.
Quiz
Ecosystem
Glossary, sister systems, and the integration seam for this room.
CRM Screen pop uses data the contact center already has: ANI, DNIS, case id. Those values may arrive in SIP headers or in a CTI event after the call is up. The CRM is not a SIP element.