Source note · Codec selection and bandwidth planning
Cisco's voice bandwidth calculation uses 40 bytes of IP/UDP/RTP header (20 IP + 8 UDP + 12 RTP), 18 bytes of Ethernet Layer 2 header including FCS, and 2 or 4 bytes when compressed RTP (cRTP) is used.
Checked 2026-09-24
- Vendor
- Cisco
- Product
- Cisco IOS voice
- Subsystem
- bandwidth calculation
- Deployment
- on-premises
- Region
- not restricted
- Release range
- current as of 2026-09-24
- Checked
- 2026-09-24
Sources
- Modify Bandwidth Consumption Calculation for Voice Calls — Cisco · tier 2 current vendor documentation · Section 'Bandwidth Calculation Formulas' and notes under 'Voice Codec Bandwidth Calculations'
Cite this note
APA
WarmTransfer. (2026, September 24). Codec selection and bandwidth planning: source note bandwidth-codec-planning-cisco-header-sizes. WarmTransfer. https://warmtransfer.net/knowledge/claims/bandwidth-codec-planning-cisco-header-sizes
BibTeX
@misc{warmtransfer-claim-bandwidth-codec-planning-cisco-header-sizes,
title = {Codec selection and bandwidth planning: source note bandwidth-codec-planning-cisco-header-sizes},
author = {{WarmTransfer}},
year = {2026},
url = {https://warmtransfer.net/knowledge/claims/bandwidth-codec-planning-cisco-header-sizes},
note = {Source note bandwidth-codec-planning-cisco-header-sizes, checked 2026-09-24}
}