Chapter 1: Description and Requirements
Chapter 1: Description and Requirements
The E3Switch converters described herein are used in pairs to connect two Ethernet LANs via either one or
two E3 or T3/DS3 links at up to 88Mbit/s actual user data rate per direction. The LAN interface is RJ45
100/1000BaseTX copper or SFP 1000BaseX fiber optic. The telecom link must be point-to-point and may
support either framed or unframed data. The two converters must have an E3 or T3/DS3 link between
them. Reverse topology to bridge an E3 or T3/DS3 data stream over an intermediate IP or Ethernet LAN is
not possible with this product; for that, consult our TDM over Packet documentation.
The converters must be used in pairs. Single-ended operation is not possible, i.e., connecting to a DS3/E3
PPP/HDLC backbone or ISP remote router is not supported.
For ease of installation, the converter does not require a configuration setup and will typically work
immediately upon connection of LAN and telecom cables.
The hot-swappable converter card draws a minimal amount of power and may be purchased in a variety of
chassis. Standalone, single units ship in high-reliability, fan-free 1U chassis with rackmount brackets and
are available in a 100-240VAC or a
±35-
75 volt DC models. NEBS-III, redundant-power multicard
chassis are available in 6-slot/1U and 20-slot/3U versions.
Both HTTP and SNMP management of the converters is possible either in-band through the LAN or
telecom ports or out-of-band through either LAN port if the software option to enable the second LAN-SFP
port has been purchased. Firmware shipped prior to June 2007 does not support management.
Remote firmware upgrade to a converter is possible through either the LAN or DS3/E3 connection (for
converters containing firmware shipped after February 2007).
If the dual DS3/E3 option or password upgrade has been purchased, then LAN data is forwarded at twice
the single-DS3/E3 data rate across the link. The converter will monitor the telecom connection status and
automatically switch to an available link should a single DS3/E3 link fail. Firmware shipped after April
2008 has the ability to maintain strict packet order at the receiving end of dual DS3/E3 links if desired and
automatically choose the lowest-latency DS3/E3 path during transmission.
The converter will buffer data, and implements flow-control and quality-of-service mechanisms to eliminate
data loss. This model will
not
perform MAC address filtering to forward only required packets across the
telecom-speed link.
The converters at each end of the telecom link are identical and each can generate its own DS3/E3 transmit
clock if so configured. There is no master/slave relationship. If spare units are being purchased, only one
rather than two is required since there is not a specific master or slave unit.
The converter will pass all error-free packets unaltered which do not exceed 1650 bytes in length (or 9600
bytes with jumbo-frame upgrade). This included stacked-VLAN, QinQ frames and all modern router
protocols.
The converter has been designed with attention paid to maximum throughput, minimum latency and
minimal packet loss – containing efficient, path-bonding functionality not found in other products. The
converter is often both a cost-effective and bandwidth-efficient alternative to routers. Even when connected
to a LAN port from a router, eliminating a router telecom card can free up expensive, limited, router
backplane bandwidth .
The converter is plug-and-play and can often be installed in several minutes. Network topologies and
configuration settings of equipment connected to the converter can be complex, however, so additional time
should be allocated to achieve a properly functioning system.
6
