Pass-through servers and hunt groups

Pass-through is a process that runs on a server and establishes connections between the users and servers connected to that server and other servers. Pass-through connections use an intermediary server as a "stepping stone" to connect the two servers.

Pass-through is useful in two instances:

  • When two servers connect directly -- When a client (in this case, either an HCL Notes® client or an HCL Domino® server) does not share a common protocol with a destination server, you can set up an intermediary server that runs both protocols as a pass-through server to enable the client to connect to the destination. For example, suppose that Server A, which runs only NetBIOS, needs to connect to Server C, which runs only TCP/IP. If Server B runs both NetBIOS and TCP/IP, Server B can act as a pass-through server to allow communication between Server A and Server C.
  • When you want to provide additional security -- Domino® lets you apply additional access controls to pass-through connections, enabling you to use pass-through connections to act as an proxy server for filtering NRPC traffic. You can specify the users and servers that can access a server as a pass-through destination, as well as those that can use a server to make pass-through connections to another server. Internet protocols such as HTTP, IMAP, and LDAP cannot use a Domino® pass-through server to communicate with a destination server.

You can set up a pass-through server so that it leads to additional pass-through servers as well as directly to a pass-through destination server. Thus, you can chain together multiple pass-through connections to enable a client to pass through several servers until it connects to a given target server.

Pass-through access is valuable to Notes® client users as well. When you provide a Notes® client with access a to a pass-through server, the client user can connect to a single server to access other network servers. For remote users, this enables access to multiple destination servers on the same LAN over a single phone connection. Using a pass-through server this way saves the time and expense of configuring many individual servers to support modem connections and of requiring Notes® client users to use multiple phone calls to access multiple servers.

Pass-through Logging

To enable to monitoring of pass-through traffic for security reasons, after you configure a server as a pass-through server, the server log (LOG.NSF) records information about pass-through sessions established through that server. For example, the log records information about users who access this server for to make pass-through connections to other servers.

Hunt groups

Note: Hunt groups use a direct dialup modem (X.PC) connection. Support for this type of connection is available only in releases of Domino® earlier than release 8.5. You may continue to use Domino® Administrator 8.5 to configure and maintain direct dialup modem support, but only on servers running releases earlier than 8.5.

If your telecommunications infrastructure supports a hunt group -- that is, a pool of modems that are connected to different phone lines but that use a single phone number -- you can configure Domino® servers and Notes® client users to connect to a hunt group on a pass-through server. Whenever a call is made to the hunt group number, the incoming call is routed to the first available modem in the group.

You can use a hunt group with one or more pass-through servers. If more than one pass-through server is used in the hunt group, to allow any pass-through server in the hunt group to receive a call and route it to the destination server, the calling server or user must use a Hunt Group Connection document.