AG Projects Open Source platforms - Boston 2005 Open Source carrier-grade platforms Adrian Georgescu AG Projects

AG Projects Open Source platforms - Boston 2005 Current telecommunications landscape Circuit switched networks (SS7 and ISDN) reached their end-of- life Replacement for signaling protocols has been proposed by ITU (H323) and IETF (SIP) Other alternatives: MGCP/Megaco, Skype, Skinny, IAX All vendors support SIP today, it is a common denominator in the vendor landscape From the old PSTN only the E.164 numbering plan remains

AG Projects Open Source platforms - Boston 2005 SIP protocol features SIP is a horizontal protocol which allows end-points to find each other and initiate sessions over the Internet (any type of sessions) Intelligence is distributed among participating nodes SIP makes use of other proven protocols for addressing, security and scalability, it did not re-invent the wheel (DNS, HTTP, TLS) SIP allows both telephone numbers or format for addressing SIP enabled convergence between fixed and mobile networks, you can change access medium, device or provider and it still works.

AG Projects Open Source platforms - Boston 2005 Business models based on SIP Classic PSTN termination service with per minute charging ADSL service complement (bundling Internet access with VoIP) Telephone numbers can be sold separately (recurrent charges) Company PBXs interconnected via IP (project based approach) SIP service subscription (free calls to other SIP phones) Closed garden/walled garden models - better chose Open, the more subscribers are restricted the bigger the churn

AG Projects Open Source platforms - Boston 2005 Open garden versus Walled garden Walled gardens so far have been motivated by poor implementations, lack of clarity over new business models, the push of session border controllers PSTN and E164 numbering plan were a success because one was able to connect to everybody else (universal service) Is important to allow dialing of both E164 numbers and SIP URIs By the time you finish building up your walled garden, the customers will be safely outside - Adrian Georgescu If you can dial a SIP URI and you can be called by a SIP URI than you have access to VoIP otherwise is just an emulation of classic PSTN - Henry Sinnreich

AG Projects Open Source platforms - Boston 2005 Open Source versus Closed Source Todays speed of development can be achieved only through OS Before: black box switch developed by a vendor, the switch worked in controlled environment (SS7 network). Development cycle was long and testing in a closed lab was enough Today you have a combination of services/servers: DNS, SIP, ENUM, NAT traversal, all are exposed to the Internet, all are moving targets, all are subject to continuous development On the Internet the things work differently, is a not a controlled environment DoS attacks can bring down a service, the solution is to use similar countermeasures, a distributed service infrastructure

AG Projects Open Source platforms - Boston 2005 Deployment stage During installation of an Open Source solution, the Service provider can learn how to build the platform which is useful for disaster recovery should such event arise: Installation log Source code Documentation for individual components As-built schematic (platform blueprint) Further customization of deployed solution

AG Projects Open Source platforms - Boston 2005 Business resilience SIP is a moving target. The companies developing SIP are fairly young, there are risks which can be minimized: Large operators should not bet on one vendor alone. Use a main vendor for the initial solution and a back-up vendor. They should know about each other and should work together Two vendors may develop a stronger product and solve interoperability issues that will appear when you connect to other SIP networks Get/train specialists in house, get familiar with the Open Source solutions used Business is more secure with a large knowledge base

AG Projects Open Source platforms - Boston 2005 Requirements for carrier-grade SIP services Compliancy with standards, interoperability and best practices Knowledge base, the biggest Open Source unfair advantage Integration with other systems: PSTN interconnect, integration with other carrier business units like provisioning and billing Solution scalability and survivability

AG Projects Open Source platforms - Boston 2005 Ingredients for carrier-grade SIP services SIP signaling (Proxy/Register/Redirect) E.164 number translation (ENUM) NAT traversal capability (ICE in the client or far-end server based) Mediation and accounting (critical for a carrier business) Provisioning (critical for a carrier business) Emulation of existing telephony services (class 5), Applications (Voic , Voice to , Conferencing, Interactive messaging and Presence), End-user devices (software or hardware)

AG Projects Open Source platforms - Boston 2005 SIP signaling (SIP Proxy/Registrar/Redirect) SIP Express Router, the largest SIP Proxy/Registrar installed base today. SER is used by major carriers all over the world, is the best example of how Open Source community could merge quickly into a product features that commercial vendors later add to their offerings OpenSER, a fork of SER with enhanced carrier-grade features has been spawned at: Visit Booth 943 to get in contact with some SER developers

AG Projects Open Source platforms - Boston 2005 ENUM and number portability ENUM is a DNS based system, the solutions are also coming from the Open Source community (BIND and Power DNS) ENUM link VoIP islands together ENUM links PSTN with IP ENUM provides an internet based number portability solution (as opposed to closed IN systems) - Local Number portability panel on Thursday 1:30 PM ENUM is a central DNS database, no need to configure individual switches anymore, save money on operations

AG Projects Open Source platforms - Boston 2005 The importance of Internet global directories Global directories are critical for increasing the adoption of Open standards: ENUM-driven number range (Austria) ENUM-driven number range VISIONng E164.org allows exchange of numbering resources between VoIP Operators DNS allows end-users to customize their SIP address by registering their own domain, my address is also my SIP address

AG Projects Open Source platforms - Boston 2005 Media Proxy - geographical distributed NAT traversal solution MediaProxy is the most used far-end NAT traversal solution deployed in hundreds of installations across the world in tandem with SIP Express Router MediaProxy is a practical example of how to implement NAT traversal without a central session border controller MediaProxy is an example of how you can provide load sharing and resilience for far-end NAT traversal without single a point of failure

AG Projects Open Source platforms - Boston 2005 How to solve scalability and survivability Carrier-grade solutions must be scalable and resilient. This should be achieved through design: Presence in multiple geographical locations Load sharing among multiple sites Resilience against DoS attacks Automatic failover on server failure or site failure Plug and play capacity upgrade with zero configuration Only a truly P2P SIP system can achieve both survivability and scalability.

AG Projects Open Source platforms - Boston 2005 Best ingredients today are Open Source SIP and DNS have been traditionally developed by Open Source community, other ingredients have been migrated to Open Source: Linux operating system: Debian ( SIP signaling: OpenSER ( NAT traversal: MediaProxy ( ENUM (BIND or PDNS CDR mediation: CDRTool ( Accounting: FreeRadius ( Database: MySQL ( Voic and voice to Asterisk ( Provisioning: SOAP/XML API

AG Projects Open Source platforms - Boston 2005 Platform blueprint

AG Projects Open Source platforms - Boston 2005

This presentation is available at: Thank you, Adrian Georgescu /SIP: