00 · Header

T7 · SIP, routing, and queues

SIP Trace Reading Lab

This lab is how you read a Webex Calling dial-plan or Cloud Connected PSTN failure without inventing a ladder. Start in Verify Call Routing. If a media session exists, open Monitoring → Troubleshooting and separate a Cloud Connected PSTN hop from a Local Gateway hop. The PSTN party’s receive metrics are absent because they are not sent to the Webex Calling cloud. Gateway debugs stay in T7-R01.

Expand all sections

01 · Executive summary

Five lines, then why it matters

• A dial plan is global for the enterprise. It chooses a trunk or a route group for matching patterns, for every user, regardless of location. [cite:1]
• If the caller is still a premises user, stop. Cloud PSTN will not take that call. Give them a premises path or move the user. [cite:1]
• Run Verify Call Routing before you open a packet capture. Pick the call source, enter the number or URI, and read the routing result. [cite:1]
• When the call connected and quality is the complaint, Monitoring → Troubleshooting keeps the past 21 days and shows whether the hop was CCPP or the Local Gateway. [cite:3]
• Webex Contact Center CCP uses its own location. Do not put endpoint devices in that same location. Outbound premises patterns are a separate dial plan. [cite:2]

02 · Map

Which console answers which question

flowchart LR
  User[Webex Calling user] --> E164["+E.164"]
  E164 --> Verify[Verify Call Routing]
  Verify --> Hop[Monitoring Troubleshooting]

03 · Core concepts

Rules that change the trace

04 · Ecosystem

Ecosystem and sister technologies

Verify Call Routing

Control Hub simulation of a routing decision. Call source is a cloud user, workspace, virtual line, or premises trunk. [cite:1]

CCPP

The troubleshooting article’s name for the cloud connected PSTN provider that relays off-net media. [cite:3]

Local Gateway hop

The other off-net path. Media comes through the enterprise, not through the CCP interconnect. [cite:3]

+E.164

The format Control Hub saves for CCP DIDs, toll-free numbers, and Local Gateway numbers. [cite:2]

Unknown extension length

n0xb944: 2–10 digits for premises-based routing. If you lengthen extensions and the PSTN provider is not E.164, inbound calls can be treated as on-premises local calls. [cite:1]

Integration edges

Sister-system trouble

05 · Flow

Order of the lab

1. Name the user. If the call starts on a premises PBX user, cloud PSTN is the wrong path. [cite:1]
2. Open the location’s PSTN connection. For CCP, Connect Type is Cloud Connected PSTN. Read the numbers under Calling → Numbers and confirm +E.164. [cite:2]
3. If the destination is on-premises, open the dial plan. It is global. The routing choice is a trunk or a route group. For contact-center outbound premises calls the voice article uses Calling → Call Routing → Dial Plans. [cite:1] [cite:2]
4. Run Verify Call Routing with the real call source and the real number. Read permissions, fraud prevention, digit patterns, intercept, and translation before you blame the carrier. [cite:1]
5. If the result says the call should leave, and a media session existed, open Monitoring → Troubleshooting. Confirm CCPP versus Local Gateway. [cite:3]
6. Hover Refusal or Failure. UnassignedNumber, NoRouteToDestination, and LocalGatewayLoop are the codes to say out loud. Permission and intercept refusals match what Verify Call Routing already displays. [cite:3]
7. If Troubleshooting is empty, the session may never have reached a Webex Calling-registered endpoint. Continue on the gateway with T7-R01. Do not wait 21 days for a hop that was never created.

06 · Config

Clicks the articles print

• Verify Call Routing: Services → PSTN & Routing → Gateway configurations, then Verify Call Routing. Cisco Calling Plan customers use Services → Calling → Call Routing for the same tool. [cite:1]
• Call source: cloud user, workspace, virtual line, or premises trunk. Enter a number or URI. See Routing Result. [cite:1]
• Create a dial plan after the trunk or route group exists. Name it, choose the routing choice, and add patterns. Bulk add is a CSV from the dial plan’s Actions menu. [cite:1]
• Unknown-number handling: Standard Behavior is the default and the one the article recommends when dial plans exist. Legacy Behavior is for old local-gateway behavior and is not recommended once dial plans are in use. [cite:1]
• Caller ID format on that same premises setting: +E.164 uses the external calling line ID. ESN uses the internal calling line ID. [cite:1]
• Contact-center CCP: create the PSTN location, Connect Type Cloud Connected PSTN, add the provider’s numbers, then confirm them under Calling → Numbers in +E.164. [cite:2]
• Contact-center outbound premises dial plan: Calling → Call Routing → Dial Plans → Create Dial Plan. Name, Routing Choice, Patterns, Save. The article’s sample range is an example of a premises block. Replace it with the numbers you actually own. [cite:2]
• Troubleshooting: sign in to Control Hub and go to Monitoring → Troubleshooting. The view covers the past 21 days. [cite:3]
• Before you finish a contact-center PSTN build, place an inbound test call and an outbound test call on the option you chose. [cite:2]

07 · Limits

Numbers the articles print

08 · Trouble

Codes and the wrong story next to each

09 · Self-question ladder

10 · Lab

One failed outbound, on paper

• Prereq: a lab org you are allowed to change. Do not run this against a production customer. Read the PSTN choice on the subscription. These articles do not name the order SKU.
• Write whether the caller is a Webex Calling user or a premises user. If premises, stop and name the path n0xb944 allows.
• Copy one DID from Calling → Numbers and mark whether it is +E.164.
• Open Verify Call Routing on the menu your subscription shows. Record the call source and the routing result’s permission, pattern, and intercept lines.
• If you have a recent test call, open Monitoring → Troubleshooting and write CCPP or Local Gateway. Write “PSTN receive not transmitted” beside the blank stream.
• If the status is Refusal or Failure, hover it and copy the code. Map UnassignedNumber, NoRouteToDestination, or LocalGatewayLoop to the row in the trouble table.
• For a contact-center location, confirm no endpoint devices sit on the PSTN location.
• Reflection: which check would have saved you from opening a gateway debug?

11 · Quiz

Eight checks

12 · Audio

13 · Interview

“I start by asking whether the caller is a Webex Calling user. Premises-originated calls cannot use cloud PSTN. CCP numbers are saved as +E.164, and the country list is the global-availability page, not a number I memorize past the article’s ‘over 65 countries.’ The dial plan is global and points matching patterns at a trunk or a route group. I run Verify Call Routing on the menu the subscription shows, with a real call source, and I read permissions, fraud prevention, digit patterns, intercept, and translation. If a media session exists, Monitoring → Troubleshooting shows the past 21 days and whether the hop was the Cloud Connected PSTN provider or the Local Gateway. I do not treat a missing PSTN receive stream as a broken capture. Those metrics are not transmitted. UnassignedNumber, NoRouteToDestination, and LocalGatewayLoop are the codes I name. Contact-center PSTN gets its own location, with no endpoints on it. If Troubleshooting is empty, I go to the gateway debug in T7-R01 instead of waiting for a hop that was never created.”

14 · Citations

Retrieved 2026-10-14. Mirrors cites/T7-R07.md.

1. Configure trunks, route groups, and dial plans for Webex Calling — help.webex — article n0xb944 — help.webex.com article n0xb944 — retrieved 2026-10-14. Cloud PSTN only for Webex Calling users. Premises-originated calls cannot use it. Dial plans are global. Verify Call Routing paths and result fields. Unknown extension length 2–10. Standard versus Legacy unknown-number handling. E.164 recommendation when the provider schema is not E.164. Emergency service address for Cisco Calling Plan in the US and Canada.
2. Set up voice channels for Webex Contact Center — help.webex — article 2dputx — help.webex.com article 2dputx — retrieved 2026-10-14. CCP in over 65 countries. Country list on the global-availability page. +E.164 storage. Dedicated PSTN location and the endpoint warning. More than one PSTN location. Calling → Call Routing → Dial Plans for premises outbound. Inbound and outbound test calls before the rest of the build.
3. Troubleshoot Webex Calling calls in Control Hub — help.webex — article frj1efb — help.webex.com article frj1efb — retrieved 2026-10-14. Monitoring → Troubleshooting. Past 21 days. Off-net via CCPP versus Local Gateway. PSTN metrics not transmitted. PSTN and Local Gateway participants not clickable. Refusal and failure codes, including UnassignedNumber, NoRouteToDestination, and LocalGatewayLoop.
4. Provision Emergency Calling in Webex Contact Center for Agents — help.webex — article nvfbjts — help.webex.com article nvfbjts — retrieved 2026-10-14. Header September 08, 2024. re-check WebRTC agents use Control Hub and RedSky. Not the Calling dial-plan tool.
5. Manage call recording for Webex Calling — help.webex — article nhvl4hw — help.webex.com article nhvl4hw — retrieved 2026-10-14. Calling recording retention. Not the troubleshooting hop view and not WxCC quality-management retention.

15 · Re-engineer later

• Open the SIP call diagram on a live call in Monitoring → Troubleshooting. The article lists it, and the on-screen ladder changes with the call, so read that diagram in Control Hub.
• Read the country and provider list on the global-availability page the day you order. “Over 65 countries” is the sentence in 2dputx. The page is the list that changes.
• When frj1efb adds or retires a refusal code, add the code here only after the article prints it.
• Gateway debugs, OPTIONS, and dial-peer hunt stay in T7-R01. Pattern grammar stays in T2-R03.
• Header dates for n0xb944, 2dputx, and frj1efb were not in the extracts used on 2026-10-14. Re-read those headers on the next pass.