SonicWall's fix for dropped fragmented INVITEs is to shrink SIP messages below MTU by removing unnecessary headers, or to move signalling to SIP over TCP.
Checked 2026-10-02
- Vendor
- SonicWall
- Product
- SonicOS
- Subsystem
- VoIP inspection
- Deployment
- on-premises
- Region
- not restricted
- Release range
- SonicOS 5.8 and later per 2020 article
- Checked
- 2026-10-02
Sources
- Some or all VoIP (SIP) invites are being dropped due to "242 Packet dropped - failed processing" — SonicWall · tier 2 current vendor documentation · Resolution section
Cite this note
APA
WarmTransfer. (2026, October 2). Troubleshooting failed calls caused by large SIP messages over UDP: source note sip-fragmentation-troubleshooting-sonicwall-fix-trim-or-tcp. WarmTransfer. https://warmtransfer.net/knowledge/claims/sip-fragmentation-troubleshooting-sonicwall-fix-trim-or-tcp
BibTeX
@misc{warmtransfer-claim-sip-fragmentation-troubleshooting-sonicwall-fix-trim-or-tcp,
title = {Troubleshooting failed calls caused by large SIP messages over UDP: source note sip-fragmentation-troubleshooting-sonicwall-fix-trim-or-tcp},
author = {{WarmTransfer}},
year = {2026},
url = {https://warmtransfer.net/knowledge/claims/sip-fragmentation-troubleshooting-sonicwall-fix-trim-or-tcp},
note = {Source note sip-fragmentation-troubleshooting-sonicwall-fix-trim-or-tcp, checked 2026-10-02}
}