INdigital ESinet SIP interconnection

Transcription

1 content and concepts INdigital telecom INdigital ESinet SIP interconnection a whitepaper guide to sip trunk connections for INdigital ESinets issued as a part of the INdigital telecom network notes series Version 1.9 ( ) last edit: 25 September :03

2 Overview: INdigital ESinet SIP originating service provider interconnection This paper describes the various options a 911 originating service provider (911 OSP) can use to establish SIP trunk based connections to NENA i3 structured Emergency Services Internetworks (ESinet) designed, installed or operated by INdigital telecom. SIP interconnection allows OSP s to deliver 911 calls for service to the ESinet, which will then result in the call being routed to the appropriate public safety answering point (PSAP). INdigital s ESinet architecture is based on the RFC-3261 standard, generally available at the IETF website: INdigital also supports the additional industry protocols: RFC-3262; RFC-3264; RFC-3311; RFC-3323; RFC-3325; RFC-3326; RFC-3398; RFC-3515; RFC-3525; RFC-3761; RFC-3824; RFC-3891; RFC-4028; RFC-4317; RFC-4488; RFC-4566; and RFC If the need arises to support services and protocols such as the 183 call signaling sub-protocol (early media or provisional ACKs,) these specifics can be negotiated per interconnect development, and a suitable technology bridge will be proposed and developed to meet individual needs. 1) SIP Interconnection specifics: A). Transport Facilities: INdigital ESinets generally support access to multiple different transport providers. Full interconnection to many multicarrier facilities, E-line/E-LAN, P2P, MPLS or VPN are just a few of the connection options available. A list of interconnection locations is available to our business partners, depending on the ESinet where connection is required. Development Environments, Pre-production Staging Environments: Secure IP tunnels over commodity internet connections are fully supported, and are often used for development and pre-production testing. Production Environment: INdigital recommends a dedicated, private connection arrangement. The service provider s transport facility can terminate to any of INdigital s POP locations. A list of these locations is available to our business partners. 2 of 10 content and concepts INdigital telecom

3 INdigital recommends the use of redundant and diverse transport facility arrangements and redundant hardware where possible to maximize resiliency and eliminate any single point of failure. Industry standards recommend to two points of geo-diverse private connections with an internet based VPN backup. INdigital s minimum requirement are one point of interconnection via private connection (T1-Data, Ethernet, MPLS, E-line/E-LAN.) The secondary or redundant connection can be an additional private connection or VPN via the public Internet. B). Transport Protocol: The INdigital network currently supports IPv4 connections. IPv6 is not fully supported at this time due to the immaturity and slowly evolving industry support of the protocol. C). SIP Termination: The INdigital network has multiple SIP Session Border Controllers (SBC) available for SIP termination. SIP termination is, however, an inexact science, and the exact method used by an OSP will need to be engineered on a case by case basis, thereby fully defining the method of interconnection in this document will use broad, general terms. D). ESinet / SBC Security Measures: INdigital requires that the OSP use some form of SBC at their OSP network to transport platform handoff location. The SBC is primarily used for topology hiding, RTP proxy and normalization of the SIP protocol. If the interconnecting company cannot provide these SBC functions, INdigital can suggest a configuration that meets industry standards and practices. E). Call Signaling requirements: SIP call signaling will use 911 as the called party number in cases where the ESN (emergency service number) is not already known, (i.e. for calls that are not pre-selective routed.) The Calling Party Number (CPN); P-ANI/ESRK; or ANI can be used if the ESN of the Emergency Services Agency is known. The ESN can also be signaled using INdigital s ESN number as the called party. Currently, only Called and Calling party fields are used for selective routing within the ESinetwork. Deviation from these configurations are negotiated on a per interconnection specific basis. 3 of 10 content and concepts INdigital telecom

4 F). Geo-Routing: For information regarding the ability to geo-route calls using PIDF-lo body or header fields, contact INdigital for an expanded discussion of this service feature. This mode of operation is defined in RFC-2778 and RFC These configurations can be negotiated on a per interconnection basis. 2) INdigital SIP profile: SIP methods supported SIP timer values used SIP OPTIONS (pings) supported? Support/require PRACK? SBC Vendor/Model/Software Version Support/require Early Media? Calling Party one of the following: From: P-Asserted-ID:, Remote-Party-ID: Called Party (To:) RTCP DTMF Relay ACK, BYE, CANCEL, INVITE, OPTIONS (required) T1 500ms; T2 4sec; T4 5 sec Yes No ACME Packet Net-Net or Similar Egress CPE/Gateway dependent Caller DN or ESRK of calling party preferred Agreed upon per connection Optional RFC-2833 or in-band 4 of 10 content and concepts INdigital telecom

5 3) INdigital Media Profile: Supported codecs Sampling rate UDP/TCP G.711u 20ms UDP (unless otherwise agreed) Port Signaling 5060 RTP port range Support transcoding of media? RTCP enabled? Expected network delay for RTP No This is user agent specific. Certain CPE/Gateways associated with ESinets will support it, but not all. Internally <40ms. However, we often deploy large scale ESinets using multiple transport types. 5 of 10 content and concepts INdigital telecom

6 4) SIP Message Example A). INdigital can provide message examples upon request. B). Functional block diagram 6 of 10 content and concepts INdigital telecom

7 INdigital contacts INdigital ESinet SIP originating service provider interconnection Parties needing additional information about INdigital ESinet SIP trunking or other general inquiries regarding NG9-1-1 or E9-1-1 trunking are invited to write or call: Brent Cummings, Director of Operations bcummings(at) indigital.net or Kent Claussen, Chief Technical Officer kclaussen(at) indigital.net or Bobbie Carter, Project Manager bcarter(at) indigital.net INdigital Telecom 1616 Directors Row Fort Wayne IN Phone toll free: the remainder of this page is intentionally blank 7 of 10 content and concepts INdigital telecom

8 Glossary of Terms INdigital ESinet SIP originating service provider interconnection ANI: Automatic Number Identification, describes the actual telephone number of a calling party. CPE: Customer Premises Equipment DTMF: Dual-tone multi-frequency signaling ESN: Emergency Service Number, a numerical identification for a specific emergency service provider. In this case used to assist in routing Emergency Calls for Service. ESRK: Emergency Service Routing Key. This generally describes a nondialable telephone number used as a record reference number for looking up caller location information for wireless, or similar nomadic type calls, for emergency services. See also P-ANI Gateway: An entrance point from one network to another G.711u: The default modulation scheme for Internet Protocol (IP) private branch exchange (PBX) vendors. G.711 digitizes analog voice signals. IETF: Internet Engineering Task Force. A standards setting body for the development and adoption of recommended standards defining IP and SIP protocols (among others.) INdigital Emergency Service Internetwork (ESinet): A private IPv4 voice and data network owned and operated by INdigital telecom. The network can receive, selectively route and deliver telephone calls (public to authority) to emergency communications centers using VoIP technology. IP: Internet Protocol. Also referred to as IPv4 in this white paper to specify that the network operates using Internet Protocol version 4. P-ANI: Pseudo Automatic Number Identification. See also ESRK PIDF-LO: Presence Information Data Format Location Object. (See also RFC 2778 and RFC 4119) POP: Point of Presence PRACK: Provisional Response Acknowledgement 8 of 10 content and concepts INdigital telecom

9 RFC: Request For Comments a distributed method of the development of standards used by the IETF. RTP: Realtime Transport Protocol RTCP: RTP Control Protocol SBC: Session Border Controller, is a network element used in VoIP networks to exert control over the signaling (and usually the media streams) involved in setting up, conducting, and tearing down telephone calls or other interactive media communications. SIP: Session Initiated Protocol T-1: A digital transmission link with a signaling speed of Mbps. UA: User Agent UBE: Unified Border Element VoIP: Voice over Internet Protocol the remainder of this page is intentionally blank 9 of 10 content and concepts INdigital telecom

10 Appendix A This appendix contains the physical address and NPA-NXX of the ESinet SIP gateways. This appendix is for preliminary planning purposes only. The information needed to place orders for interconnection will be provided upon successful validation of the Carriers ability to meet the requirements of the ESinet users for security, interconnection, and stability. The information contained in this appendix is INdigital telecom 1616 Directors Row Fort Wayne, IN Private and Confidential Information is available to qualified originating service providers 10 of 10 content and concepts INdigital telecom