Planes
Architecture
Read a call in five planes. Jumping from a symptom to a restart skips the plane that actually failed.
- Identity. Directory number, user, device, certificate, and the PSTN number the far side will see.
- Signaling. SIP, SCCP, or the cloud call control that owns the invite. Port 5060 or 5061 is this plane.
- Media. RTP or SRTP between the addresses in SDP. A proxy can be perfect and still not see audio.
- Policy. CSS and partitions, dial-peers, Teams voice routes, Webex location PSTN choice, emergency, recording.
- Observe. CDR, CUIC call type, CQD, Control Hub, the ladder, the packet capture.
On-premises call control in this lab is Unified CM plus CUBE or another SBC. Cloud call control is Webex Calling or Teams Phone. Contact center sits on top of a number: UCCE on a dialed number and call type, Webex Contact Center on an entry point and a flow.