Voice over IP (VoIP) Enhancements

This feature allows host application developers to provide read and write access to the Subject header field.

Read access allows the host application to receive the content of the Subject header-field if it is present in the inbound INVITE message. In the SIP stack on the CSP, you can configure whether you want to report the Subject header field. Refer to the SIP Software chapter in the CSP Developer’s Guide: Internet Protocol.

In SIP, the Remote Party ID header field enables popular services as well as some regulatory and public safety requirements.

The SIP specification (RFC 2543/3261) supports each of these services independently but cannot support all combinations. For example, a caller who wants to maintain privacy and provides unintelligible information in the SIP From header field will not be identifiable by intermediaries. However, since SIP does not allow the contents of the From header field to be modified by intermediaries, the intermediaries that do not directly perform SIP authentication cannot perform certain services.

The SIP REFER message requests that the recipient contact a third party using the contact information in the request message. Prior to this Engineering Release, the CSP supported inbound REFER requests. With this release, the CSP now supports outbound REFER requests.

The CSP generates the outbound REFER message only when the host application triggers it.

Refer to the SIP Software chapter in the CSP Developer’s Guide: Internet Protocol.

The H.323 protocol resident in the IP Signaling Series 3 card enables the CSP (gateway) to communicate with other H.323 gateways and gatekeepers in the call server network architecture.

Prior to this feature, the Gateway (CSP) supported either gateway (direct calls) or gatekeeper routed calls at any one time. When the Gateway (CSP) is registered with a gatekeeper it will process all the calls as Gatekeeper routed calls.

If the CSP is registered with a Gatekeeper the CSP will send an ARQ (Access Request) message to the Gatekeeper to request information about a remote endpoint. The CSP can choose what data to look at when the Gatekeeper responds with the ACF (Access Confirmed) or ARJ (Access Reject).

Refer to the H.323 Software chapter in the CSP Developer’s Guide: Internet Protocol.

The H.245 is a control signaling protocol in the H.323 multimedia communication architecture used to exchange end-to-end H.245 messages such as:

This configurable CSP H.245 Tunneling feature permits the encapsulation of H.245 messages within H.225 message between H.323 endpoints.

Refer to the H.323 Software chapter in the CSP Developer’s Guide: Internet Protocol.

Session-Initiation Protocol. A signaling protocol used for establishing sessions in an IP network. A session could be a simple, two-way telephone call, or it could be a collaborative multi-media conference session.

A computer, attached to the Excel platform through an RS-232 or Ethernet link, from which you run the telecommunications application that controls the Excel platform.

ITU-T standard defines a set of call control, channel setup, and codec specifications for transmitting real-time voice and video over networks that do not offer guaranteed service or quality of service.

An H.323 entity on the network that provides address translation and controls access to the network for H.323 terminals and other end points. The gatekeeper may also provide other services to the endpoints such as bandwidth management and locating gateways.

Internet Protocol. Part of the TCP/IP family of protocols used to route messages and tracks the addresses of nodes.

A device that translates calls between an IP network and another network, typically the PSTN.