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sbc trunking · stub

SIP trunk capacity and concurrent call planning

Verified 2026-09-04 · 4 claims · sources tier 2

Stub. This topic has 4 verified claims and no published article. The claims below are exactly what the corpus holds today.

So far, no summary has been generated for this topic. The claims below are what the corpus currently holds.

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Claims

#ClaimStatusConfidenceVerified
1A migration that concentrates many users into a single Webex Calling location served by 1 registration-based Local Gateway can reach the 250 concurrent call ceiling at peak, producing SIP 403 rejections that look like a carrier fault rather than a design limit.
Cisco Preferred Architecture for Webex Calling — Design Overview · Derived from Registration-based Local Gateway page 23 and Location Definitions pages 60-61
inference0.602026-09-04
2A certificate-based Local Gateway trunk supports up to 2000 concurrent calls over the internet, an order of magnitude more than the registration-based model.
Cisco Preferred Architecture for Webex Calling — Design Overview · Table 2, Certificate versus registration based Local Gateway, page 27
fact0.902026-09-04
3A location using a Local Gateway is subject to a default scale limit of 250 concurrent calls, which affects how locations should be sized and split; locations using Cloud Connected PSTN are not subject to that limit.
Cisco Preferred Architecture for Webex Calling — Design Overview · Location Definitions, Deployment Aspects, pages 60-61
fact0.902026-09-04
4A registration-based Local Gateway is limited to 250 concurrent calls per registering gateway, a ceiling attributed to TLS and TCP signalling performance.
Cisco Preferred Architecture for Webex Calling — Design Overview · Registration-based Local Gateway, page 23
fact0.902026-09-04

Sources

tier 2 current vendor documentation

Cisco Preferred Architecture for Webex Calling — Design Overview

Cisco Systems, Inc. (CTG TME) · 2025-08 · accessed 2026-09-04

Cite this page

APA

WarmTransfer. (2026, September 4). SIP trunk capacity and concurrent call planning. WarmTransfer. https://warmtransfer.net/knowledge/sip-trunk-capacity-planning

BibTeX

@misc{warmtransfer-sip-trunk-capacity-planning,
  title  = {SIP trunk capacity and concurrent call planning},
  author = {{WarmTransfer}},
  year   = {2026},
  url    = {https://warmtransfer.net/knowledge/sip-trunk-capacity-planning},
  note   = {Verified 2026-09-04}
}