NetMeeting 3.0 Resource Kit

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This chapter discusses Windows® NetMeeting® 3 interoperability, including the components used to initiate conferences between organizations and the types of products and services that interoperate with these components. It also explains the extensive testing performed by Microsoft to ensure product interoperability.

Interoperability and Conference Implementation

NetMeeting interoperates with conferencing products and services that are based on International Telecommunications Union (ITU) standards. Interoperability in NetMeeting is important for the following reasons:

  • Product compatibility, rather than proprietary technologies. 

  • Communication between local and remote locations in an organization, and support for users across different platforms and networks. 

  • Support for products with varying levels of functionality and features that communicate with NetMeeting. 

The following illustration shows how NetMeeting uses Transmission Control Protocol/Internet Protocol (TCP/IP) network connections to interoperate with T.120- and H.323-compatible products over the Internet and corporate intranet. For corporate and home users, many interoperability scenarios are possible between NetMeeting and compatible, standards-based clients, servers, bridges, and gateways.


The illustration shows the following interoperability scenarios:

  • Within an organization, NetMeeting users can connect together over the corporate intranet. An H.323 or T.120 conferencing server can provide inbound and outbound connectivity with compatible clients for data, audio, and video conferencing.

  • An H.323 gateway can be used to bridge internal and external networks over a corporate firewall, supporting connections for audio and video conferencing. 

  • NetMeeting users can initiate multipoint connections with third-party T.120 clients. T.120 servers can provide administration services for this data conferencing scenario. 

  • NetMeeting users can initiate point-to-point connections with H.323 clients. Depending on the capabilities of the H.323 clients, T.120 data conferencing may also be supported in conjunction with audio and video conferencing. H.323 servers can provide administration services for this conferencing scenario. 

  • Through a gateway, NetMeeting users can connect to H.320 systems, which provide audio and video over an Integrated Services Digital Network (ISDN), and H.324 systems, which provide audio and video over standard telephone lines. Also, an H.320 server can be used for connectivity with multiple H.320 systems. 

  • An H.323 gateway also provides NetMeeting users access to people over the Public Switched Telephone Network (PSTN). 

  • An H.323 gatekeeper can be used to provide network services to NetMeeting, such as routing calls through corporate firewalls and to the PSTN and limiting the number of calls that can be placed at any given time. 

For more information about NetMeeting interoperability with other standards-based products, see the following chapters:

  • Chapter 10, "Understanding the T.120 Standard," which describes interoperability with T.120 data conferencing products 

  • Chapter 11, "Understanding the H.323 Standard," which describes interoperability with H.323 audio and video conferencing products 

Companion Products and Services Directory

For information about products and services from leading manufacturers that are compatible with NetMeeting, visit the Microsoft NetMeeting Companion Products and Services Directory at the NetMeeting Web site: 

Products and services listed in the directory are either currently available or are in development and will be available in the near future.

Note Information in this directory has been submitted by third-party manufacturers. Microsoft has not tested or certified all the products and services for interoperability. For more information, contact the appropriate manufacturer.

Interoperability Testing

Microsoft participates in two types of interoperability testing for NetMeeting:

  • In-house testing 

  • Interoperability testing with other leading manufacturers, which is sponsored by the International Multimedia Teleconferencing Consortium (ITMC)

In-House Testing

Microsoft interoperability testing is primarily done in-house. The products that are tested for interoperability are either commercially available to the public, or they are beta products provided to Microsoft by the manufacturer. The NetMeeting test team formally documents the results of interoperability tests, which include running test scripts and manually testing the software to reach the following goals:

  • Testing communication layers for interoperability. 

  • Testing conferencing programs or features that are mutually supported. 

  • Testing connections over mutually supported transports. 

  • Establishing conferences over various topologies, including conferencing servers and bridges. 

Interoperability testing does not test the quality of the third-party product; instead, it tests how compatible that product is with NetMeeting and the ITU standards. All interoperability testing involves communication between NetMeeting and a third-party product. The functions of the third-party product are verified for Windows® 95, Windows 98, and Windows NT® 4.0 platforms.

IMTC-Sponsored Interoperability Testing

The IMTC is a nonprofit corporation that promotes the creation and adoption of international standards for multipoint document and video teleconferencing. One of the primary functions of the IMTC is to sponsor interoperability test sessions and activity groups for organizations developing standards-based products and services.

The IMTC sponsors the Interoperability Trials Activity Group for T.120 (ITAG-120), and the Corporate Network, Intranet, and Internet Conferencing Activity Group for H.323. These activity groups perform the following tasks:

  • Develop plans and scripts that test the levels of networking and program interoperability among standards-based products. 

  • Organize interoperability testing events at which manufacturers can come together and test the compatibility of their product features. 

  • Define methodologies and facilities to promote interoperability testing. 

Test results show a high level of interoperability for many different T.120-based data conferencing products that connected using standard telephone lines, ISDN, local area network/wide area network (LAN/WAN), or packet networks, such as the Internet. Also, interoperability testing of H.320- and H.324-based audio and video conferencing products proved successful at the transmission level for products using ISDN, and WAN connections, and also over packet networks using H.323, Internet, and intranet connections.

For more information on product interoperability, see the IMTC Web site: 

At the IMTC Web site you'll find a schedule for interoperability test sessions, results from previous sessions, and other helpful information for organizations interested in product interoperability.