SIP protocol in detail
Ref. : IPT005
Dates : April 29 to 30, June 10 to 11, November 4 to 5, 2024
Price : 1 260 € H.T.
Duration : 2 days
Place : Paris
Schedule : 9:15 am - 12:30 am / 1:30 pm - 5:30 pm
Objectives :
- Understand the different aspects of the SIP protocol: the singlaisation, entities through which pass this signaling syntax, protocol
- How to analyze a trace exchange SIP messages
Training program :
BACKGROUND CONTEXT TECHNOLOGY
Traditional telephony networks
IP telephony, the first step of the convergence of information systems (video / unified messaging voice / data / / sharing documents)
The reference models of ToIP
- Peer to Peer Model
- master / slave model
- architectures and components of NGN solutions (MGC (Media Gateway Controller) , MG (Media Gateway) , Signalling Gateway , IP -PBX , ... )
Coding (voice and video)
- the voice encoding ( G.711, G.729 , ... )
- video coding
- different transport networks ( ADSL , PPP , FR , Ethernet, ... )
Transport mechanism / voice RTP RTCP
TECHNOLOGY
Brief History of SIP
- standardization bodies ( IETF , SIP Forum ...)
- the reference model applicable to SIP (Peer to Peer)
Presentation of a basic SIP call
- with knowledge of the destination IP address
- without knowledge of the IP address of the recipient ( Registration and called using a proxy by the caller)
- release the call
The architecture and the components of SIP
Components
- User Agent (UAC , UAS)
- Registrar
- Proxy server (Stateless , Stateful , Forking ...)
- redirect Server
- rental server
- Using the DNS
- Gateway ( SIP / PSTN, SIP/H.323 , SIP / MGCP , ... )
The protocol stack (UDP, TCP , IP, SDP , RTP , DHCP, DNS)
- the syntax of SIP messages
- the header structure / body
- queries
- responses / errors
- header fields of header
Addressing
- URI
- E164
- ENUM : correspondence SIP address / phone number using DNS
Dynamic SIP
- transactions
- call flows
- call AU busy
- interrupted before dropping appeal
- call from a SIP phone to the PSTN via a gateway
- secure messages ( timers, Cseq , PRACK optional)
SDP for negotiating media streams
Using re-INVITE or UPDATE for re- negotiation of flow
Routing SIP
- using the field 'through'
- using the DNS proxy
- Keystone signaling field 'contact'
- Use headers 'Record- Route', 'route'
Services can add value with SIP (not exhaustive)
- Message Waiting Indicator (Message Waiting Indication)
- Conferences (Pre -arrange or Ad- hoc)
- Call Forwarding
- Warning / Hold
- Call termination on occupation
- Call Transfer
- Find Me / One number follow me
- Click to dial
Fax transmission and DTMF SIP
- DTMF inband and out- of-band
- FAX via T.38 or G.711
SIP security
- SIP and NAT
- SIP Firewall
- HTTP digest authentication
- encryption of RTP (SRTP) with SDP
- the signaling encryption : TLS (sips URI , using AES)
- managing encryption keys with MIKEY
Instant messaging and presence
- the use of SUBSCRIBE and NOTIFY messages (Agent co-located)
- using PUBLISH (Distributed Agent)
- the message SIMPLE MESSAGE
Comparative table of SIP / H.323, H.248 ( MEGACO ) , MGCP , proprietary protocols
Limitations of the SIP protocol , possible changes
List of the main RFC applicable to SIP
Subscribe to the INTER of your choice :
Ilexia adapts this training session INTRA Enterprise.
Illustrations & Demonstrations :
Connecting a SIP subscriber
- trace analysis (http digest authentication, registration ...)
Call between two SIP subscribers
- trace analysis
Connecting an IP PBX / SIP softswitch with a trunk and call a subscriber to subscriber PBX Softswitch
- trace analysis
Sending DTMF SIP phone
- trace analysis
Participants :
- Engineers, technicians and technical reponsables responsible for the operational management of enterprise networks
- Prerequisites: Experience & telecom networks
- Equipment provided: Support course paper