| Microsoft Speech Server |
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The manner in which you assign telephony channels to inbound applications varies depending on the type of telephony board you are using, the configuration of your private branch exchange (PBX) switch, and the topology of your Web servers. Microsoft® Speech Server (MSS) supports four types of telephony boards: two analog boards and two digital boards. The following sections explain how to assign channels for each type of board, how to assign multiple channels to an application, and how to assign channels to an application deployed across multiple Web servers.
A channel, in the context of telephony, is the smallest subdivision of communication that carries voice information between the calling party and the called party. For MSS, channels are the voice communication links between a switched network (either public or private) and the MSS platform components that allow callers to hear and talk to MSS applications.
Voice channels carry information in either analog or digital form based on the type of equipment being used. Analog equipment carries one voice channel per physical medium or line. Digital equipment can carry multiple voice channels per physical medium. For example, a T1 line, which is the standard for digital transmission in the United States, can simultaneously carry 24 digital voice channels.
MSS supports the following telephony boards.
| Manufacturer | Model | Type | Channels |
|---|---|---|---|
| Intel | D/41JCT-LS | Analog | 4 |
| Intel | DMV160LP | Analog | 16 |
| Intel | DM/V480A-2T1 | Digital | 48 |
| Intel | DM/V960A-4T1 | Digital | 96 |
MSS supports one telephony board (analog or digital) per server running Telephony Application Services (TAS). Even though the highest-capacity board can carry 96 telephony channels, many factors influence the capacity of MSS to handle callers, such as application design and hardware topology. For more information about capacity guidelines, see the MSS Help.
Each analog channel connects to the analog telephony board using a single physical connection. To assign a channel to an inbound application, you must use the port number associated with each physical connection on the board.
If you are using more than one analog telephony board and are deploying more than one application, you should coordinate port assignments on each board with the switch administrator. With SADS, you assign channels to applications using only the port numbers on the telephony board. This could result in calls being routed incorrectly, because each board has ports numbered in the same way. In this case, you should make sure that the PBX routes calls for each application using the same port numbers for each board. For example, if port 0 is assigned to application A and port 1 is assigned to application B in SADS, the PBX should be configured to route calls intended for application A to port 0 on each board and calls intended for application B to port 1 on each board. Using this configuration, all calls for application A are always handled on port 0 and calls for application B are always handled on port 1, regardless of which board the call gets routed to or the number of boards involved.
Another option is to have a one-to-one relationship between SADS and TAS, configuring them to function exclusive of other instances. For example, if you have two sets of SADS and TAS instances running on two different computers, you can configure TAS on each computer to use the TASStartPage.aspx file of the SADS instance running on the same computer. In this way, the SADS channel assignments on each computer work exclusively with the port numbers of the telephony board on that computer.
Each digital channel is identified by the telephony switch using the Dialed Number Information Service (DNIS). DNIS provides the number that the caller dialed to the digital telephony board (the receiver of the call). With this information, SADS can then associate the dialed number with an application.
Inbound applications typically have multiple channels to handle the call load. There are two methods to specifying multiple channels for a single application:
On the SADS property page for the Web server, enter the DNIS numbers or port numbers on separate lines in the DNIS or port numbers box. For example, to assign digital channels to the application specified in the Application Manifest URL box, use phone numbers on separate lines such as the following:
4255550100
4255550101
4255550102
To assign analog channels to an application, use port numbers on separate lines such as the following:
0
1
2
On the SADS property page for the Web server, use the wildcard character (*) to represent more than one number in the number string that you enter in the DNIS or port numbers box. For example, using DNIS numbers, 425555010* represents 4255550100, 4255550101, and 4255550102. You can use the wild card anywhere in the number string (for example, *5550100 represents 4255550100 and 2065550100).
You can use the wildcard character to specify multiple ports for analog channels. For example, to assign all the ports on an analog telephony board to the application, enter * in the DNIS or port numbers box.
Remarks MSS starts applications based on the order that the appear in the SADS applications list and the status of the application (either enabled or disabled). If you have multiple applications listed, you must consider the appropriate order for applications that specify the same channels. For example, if all channels are assigned to application A (using the wildcard character (*) in the DNIS or port number box) and 4255550100 is assigned to application B, you must place application B before application A to allow callers dialing 4255550100 to reach application B. Otherwise, all callers dialing 4255550100 go to application A. To change the order of applications, select the application in the Application Manifest URL box and use the arrow buttons to the right of the list to move the application up or down. Alternatively, if you do not want any calls going to a particular application, you can clear the Enabled check box for that application, which disables it. For more information about setting application precedence and disabling applications, see the MSS Help.
To meet performance and availability requirements, you can deploy a single application on multiple Web servers and use a load balancer to manage the Web servers as a cluster. The load balancer provides a single network address for the entire cluster. To assign channels to an application on the cluster, you use the computer name of the load balancer when specifying the application manifest file in the property page of the SADS server. This ensures that all calls intended for the application use each Web server in the cluster based on availability and overall load.
Note Do not add the load balancer to the Microsoft Management Console (MMC) group as a SADS server itself. To correctly configure the MMC to use the load balancer, individually add each Web server with SADS installed on it to the MMC group. Then, in the SADS properties page, specify the computer name of the load balancer in the URL for the application manifest file. For information about load balancer capabilities and best practices, see Load Balancing Microsoft® Speech Server 2004 Enterprise Edition in the September 2004 issue of Microsoft Speech Server Newsletter.
If you are using more than one instance of