Peer-to-Peer Solutions Between Service Providers David A. Bryan CTO, Jasomi Networks October 10, 2002 – Fall VON, Atlanta, GA

Why Peer? Cost Savings –Lower completion costs –Less new equipment Extend Reach –New geographical regions –Regulatory issues Opportunities to Partner –Each may have good local client base/grasp of local market

How Can Companies Peer? 3 ways to do this –Use the PSTN Includes Back-to-Back gateways Lots of problems (cost, loss of signal, etc.) –Open connections direct to each other Issue with firewalls/NATs Often Peers are potential competitors – don’t want to leak information –Use some sort of purpose-built device IP-to-IP Gateways VoIP aware firewalls

Specific Devices : VoIP Enabled Firewall Carrier A Carrier B Fire wall corrects the signaling, and can open and close ports to allow the media to pass In many scenarios, the firewall is controlled by a Firewall Control Proxy Both carriers may have similar deployments of firewall and proxy.

Specific Devices : IP-to-IP Gateway Carrier A Carrier B Both carriers may have similar deployments of IP-to-IP Gateway. IP-to-IP gateway between carriers. Each side is a new call. Generally, doesn’t use a control proxy. Proxy terminates calls at the device just like any other gateway. (May be in DMZ using existing firewall) 

Issues with Peering NAT/Firewall traversal Anonymization Billing Authentication Legal Intercept QoS Matching Network mismatches Protocol translation Media codec translation Network Security Fraud detection/prevention Demarcation Point

NAT/Firewall Traversal Carriers still want to be able to connect with firewalls Carriers may be on separate IP spaces Need to be able to interoperate Carrier A Carrier B

Anonymization Carriers may want (or be legally obliged) to hide identity of the user who originated the call, but still need to track it internally Carrier A Carrier B Incoming call is “anonymous”, but still has traceable information (i.e., IP address) When delivered to Carrier B, identifying information may need to be stripped

Billing Billing is often generated at Gateways, but gateway is in terminating carrier’s space. Carrier A Carrier B Billing is generated here, but Carrier A would like own billing records PSTN

Legal Intercept Again, intercept is often done at the PSTN connection, but Carrier A may be legally required to provide intercept. Carrier A Carrier B PSTN ? Boundary may be only place in network where media and signaling both flow.

Authentication Need to be able to verify that users are authorized to use service, and possibly check before call for prepaid. This might need to happen on both sides. Carrier A Carrier B ? AuthSrv Ok to Call?

QoS Matching Different providers may use different marking schemes for QoS, and these need to be translated Carrier A Carrier B ?

Conversions Network Mismatches –IPv4/IPv6, particularly between countries and as time moves on –Different Network designs (transport, physical media, etc.) Protocol Conversion –H.323 to SIP translation –Various “flavors” Media Codec Translation –Need to translate to compatible, but minimize total number (particularly with wireless)

Network Security Want to hide information about your network –Who do you terminate with? –How many proxies or switches in the network? –What nodes were visited on this call? –Network topology Want to ensure no “bad” traffic from remote network –Prevent malformed requests that could crash servers –Prevent malicious requests designed to disrupt service, intercept traffic, or steal service –Detect incompatible devices sending information to your network and squash

Fraud Detection/Prevention Need to detect fraudulent uses, like multiplexing multiple calls over a single billable call Carrier A Carrier B 1 Bill is generated for only one call 3 Users are making three calls

Demarcation Point Useful for trouble shooting –Able to prove that flow is “good” up to the edge of the network Generate statistics and metrics Leg to stand on when problems arise

Jasomi’s Product Line Enterprise-to-Carrier and Carrier-to-Carrier Solutions Jasomi - The Network Boundary Experts Visit us in Booth 234