3Com SuperStack II PathBuilder S330 Reference Manual page 20

6 C 1: S D
HAPTER YSTEM ESCRIPTION
Support of Frame Relay (service and network) interworking, ATM DXI, and
SDLC/HDLC pass-through, through the high-performance serial frame data
interface.
Three expansion slots, allowing you to add other advanced features, such as
T1-DSX or E1 CBR for voice and video, voice compression, or Ethernet 10/100
support.
The following optional modules are available for use with the PathBuilder S310
switch:
The two-port CBR module services traffic generated by your existing PBXs,
channels, T1/E1 multiplexers, CSU/DSUs, and video conferencing devices. The
CBR module consists of one V.35/RS-449 and one T1-DSX or E1 interface,
which support both structured and unstructured services, in accordance with
the ATM Forum's Circuit Emulation Service (CES) specifications. The CBR
module provides a smooth migration from legacy CBR service (PBX/voice/video)
to ATM service. It also supports all relevant ATM and T1/E1 standards, ensuring
easy integration of existing equipment into new ATM networks.
The one-port Voice Compression module (VCM) is similar in function to the
CBR module, but it employs compression algorithms that allow more voice calls
to be placed through the same bandwidth. The VCM's T1-DSX/E1 interface
connects to a PBX trunk, which may use CAS or CCS signaling. Its 24/30 DS0
channels can carry individual voice, fax, modem, or data connections. You can
also bundle multiple DS0s to provide connections for high-rate applications
such as video conference or multiple-link PPP. For CCS, a DS0 is used as an
ISDN D-channel for carrying signal messages.
The Ethernet 10/100 module provides a one-port PCI Ethernet interface that
you can set for 10 Mbps or 100Mbps, full or half duplex, or configure for
autosensing.
Figure 2 shows the PathBuilder S310 switch with the optional CBR module
installed in expansion slot 7 and the Voice Compression module in slot 8.