- UK MOD
- Network managed by Cable & Wireless
- Three UK based earth stations
- 16 flyaway VSAT terminals
- Central NOC at Cable & Wireless London
- Secure monitor-only SNMP link
The MOD have a network of 16 flyaway VSAT terminals and three UK based earth stations. Once deployed, the terminals need to be monitored and controlled in the Cable and Wireless NOC in London. Additionally, a
secure, read-only, SNMP link needs to be provided to HP Openview. Each VSAT consists of a *Paradise* P300 modem and either an *Anacom* or a *Codan* SSPA. Two of the earth stations have 16 circuits available, the
third has eight.
Each earth station is fitted with a rack-mount PC running the CAM software. 16 RS232 ports are attached to the PC using an Alphawave USB-based serial extender. All the remote devices are controlled from these PCs via the async overhead channel (or engineering service channel) of the modem. IP links are used to connect the earth stations and the NOC.
Secure SNMP connection
The connection to *HP Openview* uses CAM’s SNMP ‘proxy’ ability. CAM can act as a gateway between the non-SNMP aware hardware connected to the CAM network and SNMP-based NMS systems such as *Openview* or
*Netcool*. SNMP-based control systems are regularly used in the management of large communications network and by using a CAM SNMP proxy, the RF equipment can be integrated into the same management system. The SNMP proxy can be enabled in any CAM installation, in this application a dedicated *CAM200* was installed. This is a small, low power, no moving parts appliance tailored for running the CAM software.
This link also needed to be secure, so a one-way serial connection from the existing network was made using a fibre-optic link. This was demonstrated to be unidirectional by cutting the outbound connection.
A recent addition to the network required two of the flyaway systems to be colocated and linked together so if either of the carriers were lost or there was some other outage with one of the circuits then the
distant equipment could still be monitored via the second system’s connection.
To keep each of the two colocated sites identical, a *CAM200* was added to each system. Rather than control the modem and radio over the air, the CAM200 polled the equipment locally and used the async link
back to the earth station to provide status. Locally the two CAM200s were connected using an Ethernet link. If either carrier failed, then the equipment could still be monitored using the other CAM200 as a gateway to the ‘dead’ system.
Since 2009, the network has expanded to include first one, now two in-country earth stations linked back to the UK sites and all the deployable terminals have been upgraded and are fitted with *CAM200* remotes.