Introducing the SN5200 - The Enterprise Session Border Router

by John Wu               

If you are an IT manager, you instantly become a company hero when you introduce a new, feature rich IP-PHONE on everyone's desk.  However, the same fame brings with it the immense pain of ensuring that the Enterprise Telephony solution you just deployed is secure. This requires configuring the firewall or the Edge Router to let all VoIP signaling pass through securely. Soon you realize your legacy firewall is not SIP (VoIP) aware. Thus you open yourself to the prospect of keeping all the VoIP related firewall ports open which beats the purpose of having a firewall in the first place. Such headache will often make you wonder if there is a single integrated solution designed to ease your task (and your headaches).  Well, the new Patton Enterprise Session Border Router SN5200 is the perfect solution to this problem.

SIP-trunking is an easy way for VoIP providers to manage their services. For security reasons though, Enterprises use NAPT to hide internal LAN topology from the external network.  NAPT function maps internal ip address/port assignments to external ip address/port values, and keeps track of these relationships.  However, the SIP protocol for VoIP call setup changes TCP or UDP port assignments on the fly.  When the Enterprise Edge Router's ACL/Firewall is not aware of this SIP call setup process also known as being SIP unaware, it will block the port mapping required by VoIP call setup.

The SN5200 can solve this problem. Patton's new Enterprise Session Border router SN5200 has both an ACL/Firewall and a VoIP Back-to-Back (B2B) user agent. The IP-PBX or the IP-Phone on the enterprise LAN will negotiate call set up with SN5200's B2B user agent.  The B2B user agent will in turn negotiate with provider’s SIP-trunking Softswitch on the WAN side for call setup.

SIP trunking gives unique username for each customer. Under the single user name, a customer can set up multiple simultaneous calls.  Such "single username per customer" greatly reduces the complexity for billing and account management. However, not all IPPBX’s support SIP trunking. Some of them need an individual username for each concurrent call. Also, not all Softswitches supports SIP trunking. Some of them need individual user name for each call. 

 The SN5200’s flexible VOIP OS SmartWare can easily solve this problem.  Its flexible media gateway function can map between multiple usernames and a single username on both IP-PBX to Softswitch and Softswitch to IP-PBX directions. 

In summary, the newly introduced Patton Enterprise Session Border Router SN5200 include not only a powerful SIP aware ACL/Firewall and a versatile back-to-back user agent but also advanced routing and QoS functions like Policy Base Routing (PBR), VRRP, IP loop back interfaces, IPSec/VPN and Downstream QoS. Such combination of advanced routing features and powerful VoIP functionality make it a default headache reliever for any MIS manager on the task of IP telephony deployment. So what are you waiting for? Your cape awaits you.