Source note · SIP ALG problems on firewalls and routers
The Cisco IOS NAT SIP ALG translates embedded addresses including the SDP connection and media lines, but only embedded IPv4 addresses.
Checked 2026-09-25
NAT translates only embedded IPv4 addresses
- Vendor
- Cisco
- Product
- Cisco IOS NAT
- Subsystem
- NAT ALG
- Deployment
- on-premises
- Region
- not restricted
- Release range
- IOS 15M&T
- Checked
- 2026-09-25
Sources
- IP Addressing: NAT Configuration Guide, Cisco IOS Release 15M&T - NAT TCP SIP ALG Support — Cisco Systems · tier 2 current vendor documentation · Restrictions for NAT TCP SIP ALG Support; debug output example
Cite this note
APA
WarmTransfer. (2026, September 25). SIP ALG problems on firewalls and routers: source note sip-alg-problems-ios-alg-ipv4-sdp. WarmTransfer. https://warmtransfer.net/knowledge/claims/sip-alg-problems-ios-alg-ipv4-sdp
BibTeX
@misc{warmtransfer-claim-sip-alg-problems-ios-alg-ipv4-sdp,
title = {SIP ALG problems on firewalls and routers: source note sip-alg-problems-ios-alg-ipv4-sdp},
author = {{WarmTransfer}},
year = {2026},
url = {https://warmtransfer.net/knowledge/claims/sip-alg-problems-ios-alg-ipv4-sdp},
note = {Source note sip-alg-problems-ios-alg-ipv4-sdp, checked 2026-09-25}
}