RFC 8900 explains that persistent loss of ICMP Packet Too Big messages causes persistent path MTU black holes.
Checked 2026-10-02
- Vendor
- not restricted
- Product
- not restricted
- Subsystem
- Path MTU discovery
- Deployment
- on-premises, multi-tenant
- Region
- not restricted
- Release range
- BCP 230 as published
- Checked
- 2026-10-02
Sources
- RFC 8900: IP Fragmentation Considered Fragile — RFC Editor (IETF) · tier 1 standards and regulators · Section 3.8
Cite this note
APA
WarmTransfer. (2026, October 2). Troubleshooting failed calls caused by large SIP messages over UDP: source note sip-fragmentation-troubleshooting-rfc8900-ptb-black-holes. WarmTransfer. https://warmtransfer.net/knowledge/claims/sip-fragmentation-troubleshooting-rfc8900-ptb-black-holes
BibTeX
@misc{warmtransfer-claim-sip-fragmentation-troubleshooting-rfc8900-ptb-black-holes,
title = {Troubleshooting failed calls caused by large SIP messages over UDP: source note sip-fragmentation-troubleshooting-rfc8900-ptb-black-holes},
author = {{WarmTransfer}},
year = {2026},
url = {https://warmtransfer.net/knowledge/claims/sip-fragmentation-troubleshooting-rfc8900-ptb-black-holes},
note = {Source note sip-fragmentation-troubleshooting-rfc8900-ptb-black-holes, checked 2026-10-02}
}