DMS-100 switches support only two SPIDs
per BRI: one SPID for each B channel. If both B channels will be used
for data only, you need to configure the router for both SPIDs (one
for each B channel). You cannot run data and voice over the same B
channel simultaneously. The absence or presence of a channel's SPID in
the router's configuration dictates whether the second B channel can
be used for data or voice.