Enterasys csx400 Benutzerhandbuch

10 CSX400 and CSX400-DC User’s Guide

The STAC Electronics Stacker LZS Compression algorithm provides a minimum of 2:1 firmware 
data compression for the CSX400 over PPP and Frame Relay. Firmware data compression is 
supported in software on each WAN interface for line speeds of up to 256 Kbps. per WPIM, which 
is equivalent to four DS0 channels. To use data compression, compatible equipment, (such as the 
CSX400, CSX200, and HSIM-W6 or other vendors’ equipment which conforms to the applicable 
standards), must be in use at both ends of the WAN link. This firmware method of data 
compression is used as the default, if the hardware compression module is not installed.

Cabletron Systems Inverse Multiplexing (IMUX) feature provides enhanced throughput for users 
by doing each of the following:

The IMUX function evenly distributes a data packet stream from the LAN interface through the 
two WAN interfaces on the CSX400. Since the data traffic is equally shared between the two 
Full T1 interfaces, each with 1.5 Mbps throughput, the total throughput over the logical link is 
3 Mbps, or 6 Mbps full-duplex operation with the optional hardware compression module 
(CSX-COMP/ENCR) installed in the CSX400.

The IMUX function passes packet sequence information over the WAN using the Point-to Point 
Protocol (PPP) and a WAN Encapsulated Ethernet Frame Type to support data coherency on 
both ends of the link.

Data packet streams received by the WAN Interfaces on the CSX400 at the other end of the 
WAN link are then recombined, ordered, and transmitted to the Ethernet 1 interface.

The IMUX function is fully configurable using QuickSET, which is discussed in the 

 and the MIB Navigator command set in 

.

Cabletron Systems products that support IMUX, such as the CSX400, HSIM-W6 and 
HSIM-4T1, must exist on both ends of the WAN link for the IMUX function to work.

Both bridging and routing functions are disabled when using the IMUX function.