What is SIP call Forking?
Call Forking, also known as Call Splitting. A feature of the Session Initiation Protocol (SIP) that enables an incoming call to ring several extensions, i.e., other phones, at once. The first phone to answer takes control of the incoming call.
What is SIP call leg?
A call leg refers to one to one signalling relationship between two user agents. The call ID is a unique identifier carried in SIP message that refers to the call. A call is a collection of call legs. A UAC starts by sending an INVITE.
What is Q value in SIP?
The q value is a floating point number in a range 0 to 1.0 specify as the parameter in the Contact header field. The higher the q value number, the more priority that device has. Contacts with q value 1.0 have maximum priority, so such contacts will be always tried first in serial forking.
What is branch in SIP?
The uniqueness of the branch header is used to facilitate its use as a transaction ID. A SIP transaction is a message exchange between two user agents that starts with a request and ends with a final response.
What is branch parameter in SIP?
The branch parameter is used for determining the identity of the transaction. For implementations compliant to RFC3261, the value of the branch parameter MUST start with the magic cookie “z9hG4bK”.
What is SIP forwarding?
SIP provides a mechanism for forwarding, or redirection of incoming calls. A UAS can redirect an incoming INVITE by responding with a 3xx class message such as 302 (Moved Temporarily). This response contains a contact header field with one or more URIs with new addresses that should be tried.
What is Cisco dial peer?
Dial peers are used to identify call source and destination endpoints and to define the characteristics applied to each call leg in the call connection. A traditional voice call over the public switched telephone network (PSTN) uses a dedicated 64K circuit end to end.
What is header in SIP?
A SIP Header is a component of a SIP message that is used to convey information about the SIP message. Including the correct SIP Header and correctly formatting these SIP Headers is critical to ensure that requests are successfully routed to the right recipients.
What is Rport in SIP?
This extension defines a new parameter for the Via header field, called “rport”, that allows a client to request that the server send the response back to the source IP address and port from which the request originated.
Why do we need SIP protocol?
The Session Initiation Protocol is a signaling protocol that enables the Voice Over Internet Protocol (VoIP) by defining the messages sent between endpoints and managing the actual elements of a call. SIP supports voice calls, video conferencing, instant messaging, and media distribution.
What is SIP forking and how does it work?
Sometime a proxy server forwards a single SIP call to multiple SIP endpoints. This process is known as forking. Here a single call can ring many endpoints at the same time. With SIP forking, you can have your desk phone ring at the same time as your softphone or a SIP phone on your mobile, allowing you to take the call from either device easily.
Can I use SIP forking with my android SIP phone?
For example, you would use SIP forking to ring your desk phone and your Android SIP Phone at the same time, allowing you to take the call from either device easily. No forwarding rules would be necessary as both devices would ring.
What is a call leg in SIP?
So the proxy which would fork shall add its own unique IDs to the branches it created. A call leg refers to one to one signalling relationship between two user agents. The call ID is a unique identifier carried in SIP message that refers to the call.
What is forking and why should you care?
The term “forking” comes from a computer term that means to copy or clone a direction. Applications installed on SIP endpoints are called “User Agents.” User agents can be in a smartphone/tablet, an IP phone, in your PC/laptop (softphone), or an ATA gateway.