Catalyst 6000 Modules
.. The Catalyst 6000 switch module features an 8-port Voice T1/E1 and
Services module,WS-X6608-E1 or WS-X6608-T1.
.. The Voice T1/E1 module supports T1/E1 CCS signaling, ISDN PRI
network, and user-side signaling. Similar to the AGM module for the
Catalyst 4000, the Voice T1/E1 can be provisioned for conferencing and
transcoding.The Voice T1/E1 can do mixed CODEC conferencing,
whereas the AGM only does G.711 conferencing with individual DSP
resources.