FXO-FXS Configuration

When the system detects the Foreign Exchange Office-Foreign Exchange Subscriber (FXO-FXS) interfaces, it displays the fxo-profile and fxs-profile sub-elements in tdm-config.

You can configure one or more profiles each for FXO and FXS interface, which allows you to configure different attributes. For example, you might create one profile named for the fax machine in the purchasing department and another named for the fax machine in the shipping department. The FXS card supports channels 1-4 and the FXO card supports channels 5-8. You can create separate a fxo-profile and fxs-profile for each channel, or for several channels. For example, you can set one FXO profile for channel 5 and another for channels 6-8. You can also group the profiles for routing purposes. You can assign the profiles to a route group with either the same number or a different number per profile.

For control over routing TDM traffic, each TDM profile includes the route-group number parameter that you can use to group profiles together for routing. You can route traffic by setting the following parameters for next-hop in the local-policy configuration:

next-hop = tdm:channel:<number> Use channel number to specify routing endpoints.

next-hop = tdm:group:<number> Each TDM profile includes route-group number, so that you can group profiles together. The route-group number can address several profiles for routing. During routing, the embedded Asterisk software that the ESBC uses to connect PSTN and VoIP phone services to each other picks the first available span and the first available channel when routing to a group.

next-hop= tdm:<profileName> During configuration, the system checks to confirm that no other profile contains the same routing.

Echo cancellation, which is beneficial for voice transmissions, is not beneficial for data transmissions such as fax. You can configure the system to detect the fax tone, disable the echo canceller, and set the gain to zero to avoid any distortion in the communication to the Foreign Exchange Office-Foreign Exchange Subscriber (FXO-FXS) cards.