The Erlang B model as Cisco describes it assumes random call arrival, and when all trunks or ports are occupied new calls are lost or blocked (busy tone) rather than queued.
Checked 2026-09-25
- Vendor
- Cisco
- Product
- Unified Contact Center Enterprise
- Subsystem
- trunk and port sizing
- Deployment
- on-premises
- Region
- not restricted
- Release range
- 15.0(1)
- Checked
- 2026-09-25
Sources
- Solution Design Guide for Cisco Unified Contact Center Enterprise, Release 15.0(1) - Sizing and Operating Conditions for Reference Designs — Cisco Systems · tier 2 current vendor documentation · Erlang-B Model > assumptions
Cite this note
APA
WarmTransfer. (2026, September 25). Erlang B and Erlang C for voice and contact center sizing: source note erlang-traffic-engineering-erlang-b-assumptions-cc. WarmTransfer. https://warmtransfer.net/knowledge/claims/erlang-traffic-engineering-erlang-b-assumptions-cc
BibTeX
@misc{warmtransfer-claim-erlang-traffic-engineering-erlang-b-assumptions-cc,
title = {Erlang B and Erlang C for voice and contact center sizing: source note erlang-traffic-engineering-erlang-b-assumptions-cc},
author = {{WarmTransfer}},
year = {2026},
url = {https://warmtransfer.net/knowledge/claims/erlang-traffic-engineering-erlang-b-assumptions-cc},
note = {Source note erlang-traffic-engineering-erlang-b-assumptions-cc, checked 2026-09-25}
}