The Telephony Port settings allow you to configure the physical properties of the telephony trunks (T1/E1) and analog ports (FXS). Digital trunk type selection (T1 or E1, ISDN or CAS) and analog line profile selection are done here. To configure the protocol layer settings, see the respective signaling group settings for ISDN and CAS.
Partial T1/E1 Support
The SBC Edge (SBC) supports full 23B+1D channels on T1 port and 30B+1D channels on E1 port, as well as fractional T1/E1 (limited numbers of channels). Typically, branch offices do not lease full T1/E1 resources and therefore are limited to the number of channels through which they can connect to their carrier. Partial T1/E1 support on the SBC allows the user to configure the number of B-channels on a port to match the number of leased channels. The D-channels for T1 and E1 remain numbers 24 and 16 respectively.
The effect of not using partial T1/E1 support when limited numbers of leased channels are available is that some calls (those exceeding the provisioned channel capacity of the T1/E1 line) will not be successful. For example, if a branch office has lease only four channels, and the SBC is not configured for partial T1/E1, if there are already four channels in use and the SBC attempts to place a call on the fifth or any succeeding channel, the carrier will simple reject the attempt and return a response code.
Channel Configuration on T1 Ports
The number of channels for a T1 port can vary from 1 to 23, with channel 16 reserved as the D-channel.
Channel Configuration on E1 Ports
The number of channels for an E1 port can vary from 1 to 30, with a start channel in the range 1 o 30, excluding channel 16 (D-channel).
The SBC does not support NFAS like configuration, wherein multiple T1/E1 ports may have a primary and backup D-channel and not all T1/E1 ports need to have 24th/16th channel reserved for D-Channel.
The number of channels on a port are configurable in the Port and Protocol panel of the Signaling Group when the Fractional option is selected.
Working with Telephony Ports
- In the WebUI, click the Settings tab.
In the left navigation pane, go to Node Interfaces > Ports.
The SBC 1000 supports fax on all TDM interfaces (PRI, BRI, FXS, and FXO). TDM calls, which have both call legs as TDM, use T.30 protocol. If either one or both of the call legs are IP (SIP), then the calls use T.30 protocol or inband audio. The SBC 1000 supports both the G3 and Super G3 fax protocols.
To view a Telephony Port's properties:
- Click the pop-up icon ( ) next to the entry you want to view.
- When you are finished, close the window.
Deleting Telephony Ports Overview
Ribbon SBC 2000 T1/E1 Line Card ports are automatically discovered and populated in the Ports Page area of the configuration as shown in the System tab and when Checking Port Status in the Settings tab of the WebUI. Physical T1/E1 Ports associated with hardware in the SBC System cannot be deleted.
When a line card is physically removed, its configuration is maintained but its ports will not be present when Monitoring Real Time Status. This is done for the case where you are replacing or servicing a line card.
If you have permanently removed or changed the type of line card (e.g., from an 8-port to a 2-port card), then the ports listed in the SBC configuration are no longer associated with present hardware and hence can be deleted via the WebUI. Take the following common scenario:
- Initially 8 port E1/T1 line card are installed. When the SBC system comes up, the configuration auto discovers 8 ports.
- The SBC system admininstrator powers off the SBC and replaces the 8 ports card with a 2 ports card.
- When the SBC is powered back on, the Webui will still display 8 ports in Settings tab. However, only two ports will be displayed in the Monitor view.
- At this point, the SBC system administrator can go ahead and delete ports 3 through 8.
To delete unused ports, simply select the checkbox next to the port(s) you wish delete, then click the Delete () icon located at the top of the window.
Ribbon SBC 1000 Telephony Ports cannot be deleted via the WebUI.