1 / 18

Internet Peering and PSTN Access Merit VoIP Seminar Dennis Baron April 3, 2008

Internet Peering and PSTN Access Merit VoIP Seminar Dennis Baron April 3, 2008. Outline. It’s all SIP! SIP.edu ISN PSTN Access. Well You Are Using SIP Anyway. What is SIP IETF Standard defined by RFC 3261

holleb
Download Presentation

Internet Peering and PSTN Access Merit VoIP Seminar Dennis Baron April 3, 2008

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Internet Peering and PSTN Access Merit VoIP Seminar Dennis Baron April 3, 2008

  2. Outline • It’s all SIP! • SIP.edu • ISN • PSTN Access

  3. Well You Are Using SIP Anyway • What is SIP • IETF Standard defined by RFC 3261 • “The Session Initiation Protocol (SIP) is an application-layer control (signaling) protocol for creating, modifying and terminating sessions with one or more participants.” • Can be used for voice, video, instant messaging, gaming, etc., etc., etc. • Uses URIs for addressing – single communications identity • mailto:dbaron@MIT.edu for email • xmpp:dbaron@MIT.EDU for instant messaging • sip:dbaron@MIT.EDU for voice and video • Usernames just replaced by numbers for telephone applications

  4. Soft and Hard SIP Clients • “Hard phones” • “Soft phones”

  5. Why Phone NUMBERS? • Users should not be burdened with device addresses, when it’s people they really care about • Addresses should be mnemonic and empower enterprises to manage the identities of their users sip:dbaron@mit.edu • It’s time to put E.164 phonenumbers behind us! • A.G. Bell did not say: “+1-617-252-1232, come here. I need you!”

  6. SIP User Agent INVITE (sip:bob@bigu.edu) DNS SRV query sip.udp.bigu.edu bigu.edu SIPProxy SIP-PBXGateway PRI / CAS DNS INVITE(sip:12345@gw.bigu.edu) PBX telephoneNumberwhere mail=”bob” Bob's Phone CampusDirectory Architecture (Phase 1)

  7. DNS SIPProxy SIPRegistrar locationDB Architecture (Phase 2) SIP User Agent INVITE (sip:bob@bigu.edu) DNS SRV query sip.udp.bigu.edu If Bob has registered, ring his SIP phone; Else, call his extension through the PBX. bigu.edu INVITE (sip:bob@207.75.164.131) REGISTER(Contact: 207.75.164.131) Bob's SIP Phone

  8. Old World* Emerging New World IP Desk Phones Legacy DeskPhones PSTN Cell Phones How to SIP from a 12-key phone? Solution:numeric aliases * Transitional period during which we have to support these devices will last a long time!

  9. locallyassigned IP Telephony Administrative Domain (ITAD) ITAD Subscriber Numbers (ISN) • 21232*270 • ITADs • Defined by Telephony Routing over IP (TRIP) [IETF RFC3219] • Globally unique • Lots of them (232 - 256) • IANA is already set up to allocate • ISN resolution works just like ENUM

  10. Assigned ITADs (as of 3/15/06) Academic • Internet2 • Hofstra University • UCLA • MIT • Stanford • University of Alaska Fairbanks • University of California, Berkeley • Florida State University • University of Manitoba • University of Oregon • Royal Institute of Technology • NE Worcestershire College • Trent University • University of North Carolina • University of Texas, Austin • Columbia University • UCSD • Taiwan Academic Network Corporate Enterprises • Sterling National Bank • Apple Computer VoIP Service Providers • Free World Dialup • Stealth Communications • SIPcall.com • RCN Corporation • VoIPteq • SIP Broker Government • State of Oregon VoIP Solution Providers • Tello • Iotum • Digium Other • BizFu (web hosting) • Manitoba New Democratic Party • Packet Clearing House • +36 others

  11. How Does Peering Work? Transit Transit Peering diagrams courtesy of Stealth Communications

  12. Options for PSTN Termination • May be an evolution or combination of different interconnect options • Transit via gateway to campus PBX • Direct IP connection to carriers • Access via regional or national networks • Access via commodity Internet • Brokers for peering and PSTN termination • PSTN-to-VoIP and VoIP-to-PSTN traffic can use different options

  13. Types of Peering Connections • Direct interconnection at a carrier hotel (“private peering”). • Peering typically done over Layer-2 Fabrics (also known as a NAP or IX) diagrams courtesy of Stealth Communications

  14. ENUM for Peering • IETF RFC 3761 • Single number for multiple services diagrams courtesy of Stealth Communications

  15. ENUM for Peering (cont.) Query-Response technology 1. User initiates phone call 2. Query sent to ENUM database 3. Routing information (URL) returned 4. If “true”, call established between the organizations Initiate calls using telephone numbers diagrams courtesy of Stealth Communications

  16. ENUM Server Independent non-profit company Download Numbers Peer with partner University Import Numbers Route call Over Internet2 Broker Example (Arbinet) diagram courtesy of Arbinet

  17. Considerations for Peering • Things to think about • Signaling and media can take separate routes • Diversity of paths – failover • Quality of service issues • Options for flexible services • And opportunities to consider • Disaster recovery options • Flexibility in choosing carriers • Control routing yourself in real-time • Trade minutes like a carrier

  18. Questions?

More Related