Firewalls and Security
Acme Packet - Net-Net Session Director (SIP, H.323 & MGCP)
Comdasys AG - SIP enabled Internet Appliance with Firewall, VPN, Bandwidth Management, SIP Proxy/Registrar, RTP
Converged Access - Converged Access Point is a layer-7 aware platform with advanced SIP-ALG Firewall; hardware based VPN; NAT. Traffic Management; multiport SIP; h.323 and MGCP integral Gateway. ADSL2+ and T1
Covergence - Covergence’s Eclipse(TM) provides security; control; monitoring; and interoperability functions for applications and services based SIP.
Edgewater Networks - SIP firewall and traffic shaper.
Eyeball Networks - Eyeball Networks - Scalable NAT and Firewall traversal solution for SIP end-points based on IETF standards STUN; TURN and ICE. AnyFirewall Server supports interoperability with 3rd party SIP Proxy servers.
Hotbrick Network Solutions - HotBrick - Dual WAN Firewall VPN 
- Ingate Firewalls and SIParators enable enterprise SIP communications while maintaining maximum control and security at the network edge. They also enable secure SIP trunks and remote SIP connectivity Learn More>>>
M5T - M5T develops and markets a product portfolio of SIP technologies and security solutions that focuses on real-time communication and SIP session establishment in multimedia network environments.
MediaRing - "Voizbridge" carrier class Session Controller - VoIP interconnectivity solution
Microappliances - SIP Firewall
Micromethod Technologies - Horizon is the most effective and secured solution for enabling H.323/SIP based MoIP to overcome the barriers created by firewalls and NAT. Its deployment is the simpliest and most affordable.
Nable Communications - Enterprise and Carrier class Session Border Controller(SBC) for SIP
Netscreen - Network security solutions
NFR Security - Intelligent Intrusion Defense software that enables enterprises to secure their networks against emerging threats and vulnerabilities that result from the increasing use of voice over IP (VoIP) Session Initiation Protocol (SIP) users.
Paradial - RealTunnel enables video/voice traversal through any firewall/NAT device due to support for STUN; TURN; ICE; HTTPS and all Web proxy and authentication schemes for any SIP client and User Agent
Ridgeway Systems and Software - Firewall Tunnelling Proxy
Ringchain - Reseller of networking equipment including Ingate Firewalls And SIParators(TM) in Taiwan
SafeNet - QuickSec 4.0 Client/Server Toolkit for SIP Security -
QuickSec is a complete IPSec / IKEv2 VPN toolkit that provides a robust and fully standards compliant security solution for protecting SIP.
SonicWall - SonicWall offers complete SIP and H.323 firewall solution.
Sybari Software - Antigen 7.5 for Instant Messaging (IM) is the first to provide virus scanning, document filtering, and message content scanning for Microsoft® Office Live Communications Server 2003. Utilizes Session Initiation Protocol (SIP) to provide real-time virus and content scanning of IM conversations and file transfers.
UM Labs Ltd - SIP Security Controller Solves SIP Connectivity for trunks and remote users. Features include signaling and media encryption including ZRTP support enabling secure calls to any PBX.
Xten Networks, Inc - XTunnels - A free NAT (Network Address Translation), Firewall and Private Proxy traversal solution for SIP endpoints.