Carrier Peering : SIP and ENUM Protocol Course

Like DNS, which resolves between a domain name and an IP address, the ENUM protocol allows you to find a server name from a telephone number in E.164 format.

It is used in interconnection architectures between Service Providers.

It is in reality responsible for the signaling induced from the dialing of the called number until the discovery of the NS (name server) of the SIP server responsible for the called number, and this is where all the beauty of this protocol lies in its operation for telecom purists.

We therefore offer you this module entitled 'Carrier peering: SIP and ENUM' which explains all the possible details on the operation of the ENUM protocol.

The interest of this module is that it focuses on two types of DNS records, essential for telephony, namely NAPTR and SRV.

From ENUM requests to responses including the "e164. arpa" tree and the sequence of different DNS records, this module is very well designed to not only give the participant a good understanding of how the ENUM protocol works, but also show him the benefit of implementing this protocol in modern telephony architectures.

Furthermore, it should be noted that ENUM, by its nature, gives players such as businesses and telecom operators the possibility of entering into interconnection agreements in order to facilitate the exchange of traffic.

This module therefore presents to you in a second phase the different interconnection schemes between telecom operators.

Thus, it addresses peering scenarios more generally, and more particularly the call routing strategies defined in the IP-NNI recommendations, thereby providing a good basis for analysis to engineers who wish to do so. inspire to build interconnections with their partners.

Still in this 'interconnections' section, the module offers you some IP-NNI reflexes considered very useful in your interconnections.

The module is open to everyone (engineering students & professionals in the field) and goes into detail about the information to be imparted to participants.

Learning Plan

PART I: The ENUM Protocol

• E.164 DIALING PLAN

• ENUM (rfc 6116)

• ENUM AND CALL ROUTING

• Statement of principle

• Example

• Explanation

• Why DNS

• Explanation

• Example

• DNS operation

• Architecture

• Explanation

• The domain “e164.arpa”

• OPERATION OF THE DOMAIN “e164.arpa”

• ADDRESS OF RECORD

• Example: PSTN to SIP UA

• ENUM QUERY

• DNS RESPONSE

• NAPTR registration

• NAPTR AND DNS REGISTRATION

• NATR query

• SRV type recording

• IP TO PSTN (simplified)

• RFC 6140

• DIFFERENT ENUM TYPES

• Public ENUM and its limits

• Private ENUM

• Carrier ENUM

PART II: Peering and Interconnect (VoIP and Video)

• BILLATERING PEERING

• MULTI-LATERAL PEERING

• RETURN TO ENUM

PART III: IP-NNI (Network-to-Network Interface)

• DESCRIPTION AND ARCHITECTURE

• THE BENEFITS OF SIP NNI

• IP NNI EFORT

• INTERCONNECTION LAYERS

• Network layer

• Protocol layer

• Routing layer

• IP NNI Profile

• IP NNI trust model

• Architecture

• Description

• Identities

• PSTN number

• PAI and Diversion headers

• Portability (with 'rn', 'npdi' fields)

•Codecs

• DTMF and Fax

• Troubleshooting

• SIP OPTIONS

• SIP overload control

• SIP Session Timer

• RTP loopback extension

• QoS

• SIP – Specific Details of IP NNI

• PRACK

• Normal SIP offer/answer model

• Early media

• The different forms of the P-Early-media header

• Call forwarding

• SIP transport

• IP NNI Routing

• The 'aggregate' approach

• Use of LERG and NPAC databases

• Presentation

• Provisioning & explanation

• Call flow IP to IP & explanation

• Call flow IP to PSTN & explanation

•IP NNI Routing

• The 'aggregate' approach

• Use of LERG as TIER2

• Description

• Call flow & explanation

PART IV: More Deeper about IP NNI Routing

•The 'per-TN' approach

• NPAC TN registry

• Presentation

• Provisioning & explanation

• Callflow & explanation

•The 'per-TN' approach

• NPAC TIER1 ENUM registry

• Presentation

• Provisioning & explanation

• Callflow & explanation

• INDEPENDENT ENUM TIER0/1

• Presentation

• Provisioning & explanation

• Callflow & explanation