A CS1000E system can have one of four types of signaling servers. There are two Signaling Servers that are available from a third party and there is the CP PM Signaling Server. In addition, there is support for the legacy ISP1100 Signaling Server.
The two COTS Signaling Servers that can be used are the IBM X306m Signaling Server and the HP DL320-G4 Signaling Server. Both of these servers can be configured using either Linux or the VxWorks software that the Nortel equipment uses. If the COTS signaling server is using Linux it adds the functionality of a tool called Enterprise Common Manager that allows for more advanced configuration options through a web interface than the default Nortel software allows through Element Manager.
The ISP1100 Signaling Server was used with previous releases and is supported for backwards compatibility. It is now discontinued and is not recommended, although it will function as a signaling server.
The CP PM Signaling Server uses the same hardware as the CP PM Call Server. There are a few small differences, however. The most noticeable difference is that the Signaling Server has a 40 GB Hard Disk Drive and no on-board Compact Flash. To enable the system to use the 40 GB Hard Disk Drive to load software it is necessary to set Switch 5 to position 2. Additionally, there is no security dongle on the Signaling Server.
The CP PM Signaling Server is connected either directly to the MGC or to a layer 2 switch using the ELAN and TLAN ports. Nortel recommends connecting them via a layer 2 switch. The ELAN port is used for address, data, and control signals between the various components of the CS1000E system. The TLAN port is used for telephony signaling traffic. The HSP port is not used on a signaling server. The indicator lights are the same as those on the CP PM Call Server.
The role of the signaling server is to provide SIP and H.323 signaling, IP phone signaling, and IP peer networking. The signaling server can use either VxWorks of Linux to perform these functions. The CP PM Signaling Server can only use VxWorks. A signaling server also provides the H.323 Gateway software to provide IP Peer Networking features between multiple MG1000Es and the CS1000E Call Server. In addition, it provides virtual trunk application and support for IP terminals. It can be configured with a survivability configuration and a load-sharing configuration. Each signaling server can support up to 5,000 IP users and a maximum of 1,800 SIP and H.323 trunks. Of these 1,800 trunks, a maximum of 1,200 H.323 trunks are available. This maximum can only be achieved if H.245 tunneling is enabled. If the server is running Personal Directory, Redial List, and Caller List, a maximum of 1,000 IP users are supported per Signaling Server.
A Signaling Server has a number of software applications that are installed to provide functionality. This includes the SIP/H.323 Gateway Signaling Software (for virtual trunks), IP Line Software (including the Terminal Proxy Server), a Network Routing Service (NRS) application, the Element Manager web server, the NRS Manager web server, and an application server that includes Personal Directory, Callers List, and Redial List.