- Security TWENTY
- Women in Security
GarrettCom Europe has provided large quantities of hardened Ethernet switches as part of the latest expansion of Turkey’s city-wide CCTV. The firm says their switches were selected for their ability to handle the demanding high-bandwidth traffic of multiple video cameras, and to withstand Turkey’s typically arduous site conditions without special protection. The switches had to cope with extremes of temperature, resist the effects of humidity and be immune to corrosion.
Turkey has been rapidly expanding city-wide surveillance, with the aim of providing video-based security in every major city in each of the country’s 81 provinces. Each installation of its so-called Mobese Urban Information and Security Systems provides all of the electronics and software needed to ensure urban security. Cameras are mounted high on poles in critical areas, with the live video monitored and recorded at local police stations and emergency call centres. Many installations have been carried out by Turkish company Vitel. Founded in 1993, Vitel provides turnkey network and network security.
For its Mobese installation, Vitel specified Pelco analogue cameras, which would feed the video to IP encoders. GarrettCom are one of Pelco’s PartnerFirst members. From the encoder, the video data is fed via Fast Ethernet UTP to an Ethernet switch. Video traffic from all of the field switches around the city is then fed over a Gigabit Ethernet fibre-optic connection to a central layer 3 switch, which in turn routes the data to a master monitoring and recording station, and to several local viewing stations. The master viewing station can monitor the whole city, while the local viewing stations each monitor specific areas of the city.
The choice of field switch for Vitel was critical. The field cabinets that house the network switches – along with video encoders, UPSs and various sensors – are exposed to direct weather conditions, with no special shelters or buildings for protection. This meant the switches had to be hardened to withstand extreme ambient temperature variations as well as the characteristically high humidity. They also has to deliver the requisite performance to handle the high data rate of a live video feed – as high as 5Mbps – and the multi-cast traffic from clusters of CCTV cameras – traffic which can, if not managed, quickly exceed the available bandwidth of the network. It was also important that a degree of redundancy could be built into the network, with fast link recovery in the event of a problem.
When switches from two other vendors fell at the first hurdle in field tests by failing even transmit the live video traffic at the required frame rate and video quality, Vitel turned to GarrettCom Europe. To meet the demanding application requirements, Vitel specified GarrettCom ES42 6-port Ethernet switches to take feeds from clusters of up to three cameras, and 6KQ 12-port Ethernet switches to take feeds from clusters of up to six cameras.
Both switches offer flexible, user-definable configurations of ports. The ES42 provides six ports, four of which are 10/100 copper ports, with the remaining two available for configuration as 10/100 copper or 100Mb fibre. The 6KQ is a heavy duty field switch with up to 16 ports. The base unit has four 10/100 copper ports, and the remaining ports can be configured with flexible combinations of 10/100/1000 fibre and copper ports, including a maximum of two gigabit ports.
For the Mobese application, both switch types have high IP ratings and hardened for outdoor use, rated for temperatures between minus 40 degrees C and plus 75 C, and conformally coated to resist humidity and corrosion. In addition, the 6KQ provides an advanced thermal design which eliminates the need for vulnerable internal fans by using a heavy-duty aluminium case with a ribbed surface for heat dissipation.
Importantly for Vitel, the switches are available as standard with IGMP snooping software, providing the required management of the multi-cast video traffic. The IGMP prototol is a standard defined in RFC1112 and RFC2236, and specifies how a host can register a router to receive specific multicast traffic. A further benefit of IGMP is that it provides a means to combine the video-over-Ethernet traffic stream from cameras with other typical LAN data traffic, enabling a single, common LAN system to be used for both types of traffic.
Traditionally, IGMP support has meant specifying costly layer 3 routers and switches, but with GarrettCom’s latest software development the company’s layer 2 Ethernet switches support IGMP as standard. Instead of broadcasting multicast traffic across all its ports, a GarrettCom layer 2 Ethernet switch with IGMP support provides tighter control of multicast traffic. The need for multiple layer 3 products is eliminated and costs are dramatically reduced.
To meet Vitel’s requirements for network redundancy, the switches were provided with GarrettCom’s MNS-6K management software, including Link-Loss-Learn (LLL) functionality. This provides self-healing, fast recovery functions for redundant LAN structures. There is a choice of redundancy options, including STP, RSTP, and GarrettCom’s own standards-based S-Ring recovery technology. GarrettCom markets its products through a network of resellers, OEMs, system integrators, and distributors worldwide. For more information on GarrettCom and its products, visit www.garrettcom.co.uk.