Ethernet over serial: HSSI,RS-232,EIA-530,X.21,V.35,RS449 or V.36

Please Note:

The LH1000 product has now been superceded by the much more flexible and fully manageable MetroCONNECT LHM1000 product which offers advanced functionality. The LH1000 is no longer available.

LAN Extension over Satellite

• Must be used in pairs.
• LAN extension over satellite links
• 10 / 100BaseT auto-negotiating LAN port
• Filtering of local packets
• Efficient HDLC packet handling on WAN port
• HSSI interface at up to 100 Mbps
• Multi-standard serial interface supports RS-232, X.21, EIA-530,V.35, V.36 at up to 20 Mbps
• Mixed Tx and Rx interface operation e.g. HSSI Tx & EIA-530 Rx
• Asymmetric operation
• Easy to install & maintain
• Integral auto-sensing power supply (100-250V AC or -40V DC versions)
• 12-24V DC power supply available on request
• Compact modem style unit, built to European standards
• Rack mounting kits for 2 or 18 units available

The LAN interface is auto-sensing and supports 10M, 100M, full or half duplex working. Manual selection of 100BaseT FD operation enables connection to fixed config router ports. It is presented as an RJ45 connector and offers automatic MDI/MDI-X interface selection to obviate the need for cross-over cables. The LAN interface utilises an efficient HDLC encapsulation with address learning and filtering at up to 148810 packets per second. Rate decoupling is supported by means of a 1000 packet SDRAM buffer store, and no packets are lost providing that the sustained data rate is below the DTE serial port speed.

Two DTE ports are provided. They can operate at asymmetric speeds since they are clocked using the DCE supplied Send & Receive Timing signals. The ports are:

• a high speed HSSI DTE port using a standard 50-way SCSI-2 connector at a DCE clock rate of up to 100Mbps
• a low speed multi-standard DTE port (e.g. EIA530) using a 44-way D-Type connector at clock rates up to 20Mbps

The low speed multi-standard port offers the options of RS-232, EIA-530, X.21, V.35, RS449/V.36 interfaces, depending upon the type of interface cable fitted to the port. See the Order Info tab for details of the cables that Metrodata supply for use with the LH1000.

HSSI Interfaces on Satellite Modems can go as high as 90Mbps, but typically HSSI is only used up to 51.84Mbps or STS-1. This is the "theoretical" maximum speed of HSSI (also known as EIA/TIA612). This limitation is due to router HSSI Modules unable to go any faster than 52Mbps. The other problem with running HSSI at high speeds is that the line driving capability is drastically reduced with higher data rates. With the LH1000 it is possible to support an Asymmetric Satellite service with HSSI used for the higher rate and EIA530 used for the lower rate. This can be a more cost effective solution than buying 2 x HSSI Satellite Modems.

The LH1000 supports a maximum packet size (MTU) of 1536 bytes which is sufficient to transport double VLAN tagged frames (Q-in-Q).

The LH1000 can easily be rack mounted in either a 1U two unit rack mount kit, a 6U eighteen unit rack mount kit.