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.
  • 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.