S.CON1M TX/FX Managed Converter
4
1 – Overview
A media-converter may be defined as a device connecting two active network
components point-to-point over a media that is different from the ports of at least one
of these devices.
While Media Converters are considered part of the cable plant, in many cases they
must be remotely managed as any other network device. In particular this is true in
mission-critical, fully managed networks as well as in networks dispersed over large
areas to allow efficient control and maintenance. The
S.CON1M
is the
only
SNMP
managed
single
channel Media Converter available in the market.
While vendors offer such feature for large chassis based systems only, the need for
management is more intense in single channel devices, being deployed away from the
main wiring closets. Out-of-band management assures independence of the control
channel for enhanced system reliability.
SFS
(Single-Fiber-Strand) versions of the S.CON1M make it a superb choice for
suitable installations saving 50% of the entire cable plant
An ideal media-converter should be a transparent element in the network, and its
ports may be considered as integral parts of the devices interconnected by it.
The IEE802.3u standard defines network span in terms of distances and bit times.
Conventional 100Base-TX/100Base-FX media-converters are based on repeater
technology, and they form a part of the collision domain created by the interconnected
devices. Therefore, the delay they introduce in the network severely affects the
allowed distances. Furthermore, if two class II repeaters (i.e., 2 hubs) are already
present in the same collision domain, then the use of a conventional converter is not
allowed as the repeater count may - in such case - exceed the limits. In all other
cases, meticulous PDV (Path Delay Value) must be performed prior to establishing the
possible distances for both the fiber optic (F/O) and copper segments.
The S.CON1M implements a non-repeater, full re-timing design. It creates a
B
uffered
M
edia
D
omain (BMD) over the F/O link, thereby eliminating all the above-mentioned
limitations.
The BMD created by two S.CON1M devices always operates at maximum
performance - 100Mbps/Full Duplex - while interconnected devices may operate at
different rates and modes. This provides full flexibility when planning a network.
The S.CON1M supports the
Far End Fault
(FEF) feature.
Far End Fault occurs when the signal detection is logically false from the receive
(incoming path) fiber port. When the S.CON1
detects a F/O Link Loss condition, the
unit will automatically send a Far End Fault signal to the remote device (on it outgoing
path). The remote device should support the same FEF feature and it will indicate a
Link Loss as well. (Refer to section 8 for more details).
The S.CON1M supports a bidirectional
Fault Propagation
mechanism (F>T and T>F).
When the S.CON1M senses a loss of F/O Link, it will automatically cut its TP port link.
If the S.CON1M is connected to a Master Unit, which does support Fault Propagation,
the latter will sense the loss of the F/O link and it will deliberately cut its TP port.
If the S.CON1M TP link fails, it will automatically cuts its F/O link. Thus the fault
propagates both from fiber to TP port and from TP to the fiber port.
The FP is enabled/disabled by means of the DIP switch S5.
The F>T and T>F selections are under control of the SNMP management module
(Refer to section 12 for a detailed description).
TFTP for software upgrade downloading and Telnet are also supported.
