Source note · SIP ALG problems on firewalls and routers
One-way or no audio is a plausible result of an ALG that rewrites the SDP c= or m= values incorrectly, or opens RTP pinholes for the wrong address or port. The far end then sends RTP to a destination that does not reach the phone.
inferred · Checked 2026-09-25
- Vendor
- multi-vendor
- Product
- SIP through NAT
- Subsystem
- media path
- Deployment
- on-premises, multi-tenant, hybrid
- Region
- not restricted
- Release range
- current as of 2026-09-25
- Status
- inferred
- Checked
- 2026-09-25
Sources
- SIP ALG | Junos OS — Juniper Networks · tier 2 current vendor documentation · pinhole creation and SDP field rewriting sections
Cite this note
APA
WarmTransfer. (2026, September 25). SIP ALG problems on firewalls and routers: source note sip-alg-problems-one-way-audio-mechanism. WarmTransfer. https://warmtransfer.net/knowledge/claims/sip-alg-problems-one-way-audio-mechanism
BibTeX
@misc{warmtransfer-claim-sip-alg-problems-one-way-audio-mechanism,
title = {SIP ALG problems on firewalls and routers: source note sip-alg-problems-one-way-audio-mechanism},
author = {{WarmTransfer}},
year = {2026},
url = {https://warmtransfer.net/knowledge/claims/sip-alg-problems-one-way-audio-mechanism},
note = {Source note sip-alg-problems-one-way-audio-mechanism, checked 2026-09-25}
}