3Com SuperStack II, NETBuilder SI manual Parent Ports for Frame Relay

68CHAPTER 6: BASIC CONFIGURATION OF PORTS AND PATHS

unbound from their default ports and waits in the dial pool for an incoming call. When a call is received, the dynamic path that answers is assigned to a virtual port, which is standing by with the appropriate configuration information for the calling network. Because not all sites using a dial pool call the central site at the same time, it is possible to share a small group of paths with a larger group of sites. Each site that can potentially call into the dial pool has its own virtual port defined, so there are usually more virtual ports configured for the dial pool than dynamic paths assigned to it.

Parent Ports for Frame Relay and X.25

When you configure an X.25, or Frame Relay virtual port, it inherits the attributes of the path over which it is defined. It also inherits some of the attributes of its parent port.

For PPP dial virtual ports, no parent port exists because the path was unbound from its port and placed into the dynamic dial path pool.

Unlike Frame Relay and X.25 virtual ports, which are always associated with a particular path, PPP virtual ports can potentially use any path in the dynamic dial path pool. PPP virtual ports also can be used with dial-up related parameters.

For example, if you create a Frame Relay or X.25 virtual port

associated with a wide area port, the virtual port inherits port attributes from the following sources:

■Default and configured values of PORT Service parameters specified for a wide area port, with the exception PORT Service parameters that are not related to X.25 and Frame Relay virtual ports.

■Default and configured values of parameters from all other services specified for a wide area port.

To configure a virtual port, you must specify the virtual port and not the parent port. For example, if you are using the SETDefault !<port> -BCN CONTrol = Enabled syntax, you must specify the virtual port number instead of the parent port number for <port>. For complete information on the numbering convention of virtual ports, see “Path and Port Numbering” on page 69.