Source note · SIP ALG problems on firewalls and routers
On Cisco IOS and IOS XE NAT, NAT support for SIP (the SIP ALG) is enabled by default on port 5060.
Checked 2026-09-25
- Vendor
- Cisco
- Product
- Cisco IOS
- Subsystem
- NAT ALG
- Deployment
- on-premises
- Region
- not restricted
- Release range
- IOS 15M&T and IOS XE 3S guides
- Checked
- 2026-09-25
Sources
- IP Addressing: NAT Configuration Guide, Cisco IOS XE Release 3S - SIP ALG Hardening for NAT and Firewall — Cisco Systems · tier 2 current vendor documentation · Information About SIP ALG Hardening for NAT and Firewall
Cite this note
APA
WarmTransfer. (2026, September 25). SIP ALG problems on firewalls and routers: source note sip-alg-problems-ios-nat-sip-default-on. WarmTransfer. https://warmtransfer.net/knowledge/claims/sip-alg-problems-ios-nat-sip-default-on
BibTeX
@misc{warmtransfer-claim-sip-alg-problems-ios-nat-sip-default-on,
title = {SIP ALG problems on firewalls and routers: source note sip-alg-problems-ios-nat-sip-default-on},
author = {{WarmTransfer}},
year = {2026},
url = {https://warmtransfer.net/knowledge/claims/sip-alg-problems-ios-nat-sip-default-on},
note = {Source note sip-alg-problems-ios-nat-sip-default-on, checked 2026-09-25}
}