180 CHAPTER 8: PSTN G ATEWAY CONFIGURATIONTo remove a channel from a group:1 Clear the check boxes next the MAC address of the channel or channelsthat you want to remove.2 Click OK.Removing a Digital Line Card GroupYou might want to remove any group that you no longer need.To remove a group:1 Click the appropriate link:■ PSTN Gateway Configuration > T1 Groups■ PSTN Gateway Configuration > ISDN PRI Groups■ PSTN Gateway Configuration > ISDN BRI Groups2 Select the group, or groups, that you want to delete and click RemoveSelected. To select all groups, enable the Select check box.3 Click OK when the system prompts you to confirm.Modifying CardChannelsThe number of channels per span varies according to the configuration.Each channel can accommodate a single telephone call.This section describes how to modify channels for an installed card andhow to view the status of an existing channel.If you use Auto Discovery to add channels on an E1 PRI line, note that the30 channels the system discovers are numbered 1 through 15, and 17through 31. This reflects the physical channel mapping on the E1interface, in which channel 16 is the ISDN D-channel, that is used forsignaling.CAUTION: Do not modify channels unless a 3Com Technical Supportrepresentative advises you to do so. When you modify an ISDN channel,you disconnect any existing calls on that channel.Modifying a Digital Line Card ChannelTo modify a channel on an installed Digital Line Card:1 Click the appropriate link:■ PSTN Gateway Configuration > T1 Channels
