Source note · Erlang B and Erlang C for voice and contact center sizing

The Erlang B blocking probability for offered traffic E erlangs on m circuits is (E^m/m!) divided by the sum of E^i/i! for i from 0 to m. It can be computed by the recursion B(E,0)=1 and B(E,j)=EB(E,j-1)/(EB(E,j-1)+j).

field report · Checked 2026-09-25

Vendor: vendor-neutral
Product: not restricted
Subsystem: trunk and port sizing
Deployment: any
Region: not restricted
Release range: revision current at 2026-09-25
Status: field report
Checked: 2026-09-25

Sources

Erlang (unit) — Wikipedia · tier 5 independent technical research · Erlang B formula section

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-formula. WarmTransfer. https://warmtransfer.net/knowledge/claims/erlang-traffic-engineering-erlang-b-formula

BibTeX

@misc{warmtransfer-claim-erlang-traffic-engineering-erlang-b-formula,
  title  = {Erlang B and Erlang C for voice and contact center sizing: source note erlang-traffic-engineering-erlang-b-formula},
  author = {{WarmTransfer}},
  year   = {2026},
  url    = {https://warmtransfer.net/knowledge/claims/erlang-traffic-engineering-erlang-b-formula},
  note   = {Source note erlang-traffic-engineering-erlang-b-formula, checked 2026-09-25}
}

Read in context

The Erlang B blocking probability for offered traffic E erlangs on m circuits is (E^m/m!) divided by the sum of E^i/i! for i from 0 to m. It can be computed by the recursion B(E,0)=1 and B(E,j)=E*B(E,j-1)/(E*B(E,j-1)+j).

Sources

Cite this note

The Erlang B blocking probability for offered traffic E erlangs on m circuits is (E^m/m!) divided by the sum of E^i/i! for i from 0 to m. It can be computed by the recursion B(E,0)=1 and B(E,j)=EB(E,j-1)/(EB(E,j-1)+j).