Crosby Communications
IVR, SMS, Broadcasting
Telephone: 0845 200 6000
9th May 2008
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The Crosby Data Centre


Home to hundreds of servers, the Crosby Data Centre and office complex is based in the North West of England. Advanced security, fire suppression, climate control and power protection equipment provide the ideal operating environment for servers and network equipment.


We also have smaller facilities in Manchester and space at neutral collocation centres in Leeds and London. These locations are primarily staging posts on our network through which we connect with other service providers, ISPs and telecommunications operators.

Having researched the potential problems that any network must be protected against, Crosby went about designing a structured, sophisticated and robust network architecture. A well–structured network is more manageable and scalable; sophisticated use of technology balances performance with cost–effectiveness, and redundant servers contribute to a higher level of fault tolerance.

The three fundamental elements of the Crosby Data Centre architecture are:

  • Performance and Reliability
    The network's primary design criterion emphasises fast and reliable user access to services.
  • Duplication and Segregation
    From power supplies to network connections, duplicate resources and segregated paths combine to avoid any single points of failure.
  • Distributed Resources & Centralised Control
    Equipment is dispersed, but managed from a centralised hub.



Data Network


Crosby owns and operates its own data network infrastructure. We have our own IP number assignments and are consequently not reliant on any single company for our Internet connectivity.

Our network utilises fibre optic connections from BT, Telewest, Kingston Communications, Sprint, Fibrenet, Redstone Communications, Level 3 and COLT. Our Data Centre has fibre presented from a minimum of two different telecommunications providers, ensuring that no single point of failure can exist within our infrastructure.

Throughout our network, key equipment is duplicated: we use technologies including BGP and Cisco's "Hot Standby Routing Protocol" to ensure the continuous availability of a service even in the event of the failure of one piece of equipment.

BGP4 provides multiple redundant internet connections for increased speed and reliability.

Data Network Features

  • Non–internet connected gigabit network provides secure transit for data and ensures that the internet–facing network cannot become congested.
  • At least two routers running the "Hot Standby Routing Protocol" service for any server to guarantee availability.
  • All data is backed up to our tape library on a daily basis
  • Multiple firewalls protect servers from malicious traffic, viruses and trojans.
  • Replicated database servers are not Internet accessible for maximum security
  • Redundant layer 3–7 switches provide load balancing 'fail over functionality' and allow us to remove any server from the cluster to maintain it, without affecting your services.
  • A secondary web and file server cluster that replicates data from the primary cluster, providing a service should our primary servers fail.
  • A primary server and file storage cluster data is held on mirrored storage arrays.



Servers


We predominantly use Compaq and Dell servers running FreeBSD or SCO–Unix, all of which have dual Intel Pentium Xeon processors, dual 100Mbit Ethernet adapters and a minimum of 2GB of memory. Storage is spread across multiple Ultra 160 SCSI hard disk drives using Adaptec RAID controllers.

Every server on our network runs a RAID based disk redundancy solution. Should any of the primary disk drives fail, a secondary disk drive can take over the workload with no loss of service&ndhash;availability. Each server also has a replication partner that can take over its workload in the event of a problem or during planned maintenance. In addition, data on our servers is backed up to our Storagetek Timberwolf DLT tape library, with tapes being stored off site.



Feeds


The Crosby Data Centre brings fibre optic cable from multiple carriers into the facility. Fibre is delivered from different telecommunication providers and enters the building at different locations in physically separate paths that never converge. Dual fibre entry provides redundancy at the carrier level and also protection from instantaneous loss of connectivity when heavy equipment cuts a fibre line during the construction or installation of cable or gas lines.



Capacity


Our network is connected to the Internet via redundant, full–duplex fibre optic connections to multiple backbone providers. Connections are directed by redundant BGP4 routers and VLAN distribution switches.

The minimum connectivity for our fully dedicated servers is a 10Mbps network card with its own dedicated 2Mbps connection.



Monitoring


We constantly monitor all servers on our network with a range of methods, from simple pinging and web fetches to disk space and load checks. In the event of an anomaly or error, our on–call systems' administrator is alerted via pager or SMS. Our advanced SMNP monitoring system constantly monitors all services, including incoming telephone lines, connections to the mobile operators for text services and 3G connectivity for our content feeds.



Fire Detection


The Data Centre is equipped with an advanced fire detection and suppression system, including FM200 (or equivalent) gaseous extinguishing systems, which provide rapid discharge and flame suppression in the event of a fire while minimising damage to equipment and reducing danger to personnel.


Security


We take both physical and network security very seriously. We keep up–to–date with the latest security upgrades, and our firewalls protect vulnerable points and block out known unsafe networks.

Access to our servers is tightly controlled by both electronic and biometric means, through a system of airlocks and secured areas. Full entry to the Data Centre also requires a final visual check before any person can gain access to the equipment. Once in the Data Centre, activity is monitored and recorded around the clock.

Features :

  • Very early smoke detection apparatus (VESDA).
  • CCTV system covering all entrances/exits and main areas.
  • 24–hour video recording.
  • Full perimeter alarms.
  • A PAC security card access system.
  • Visual verification for all persons attempting to enter the data floor.
  • Redundant air conditioning systems.
  • Steel mesh reinforced walls & steel doors.
  • Motion sensors and security cameras.

Engineers are based on site to ensure the fastest response should any physical intervention be required at any time.



Bandwidth


We operate a redundant, scalable and bandwidth on–demand network that connects us directly to the internet backbone in both locations and is 100% powered by equipment from Cisco, the acknowledged leader in internet networking equipment.

Our primary connectivity is fed to us by Sprint and Level 3 and every server is connected directly to Cisco and 3com switches which in turn link to high performance Cisco VXR routers connected to our bandwidth providers.

We are further connected to multiple internet exchanges ensuring the fastest path for all traffic, and a high level of resilience in the unlikely event of a network failure.

Bandwidth scales according to load, ensuring that we always have enough to feed our customers requirements, and we typically keep 60% of our bandwidth in reserve to ensure we are able to cope with unexpected surges and peaks.



Power and Environmental Control


Power is supplied to the Data Centre from diverse locations and is backed up with an APC Symmetra UPS and multiple standby generators. The Data Centre is equipped with sophisticated air conditioning apparatus set at 20 degrees C and 50% relative humidity, to ensure that systems operate as efficiently as possible.

Features :

  • 2 x 1700 KVA Generator back-up @ N+1.
  • An APC Symmetra UPS system - redundant parallel formation @ N+1.
  • Close control downflow air conditioning units to guarantee stable temperature and humidity @ N+1.
  • 2 independent AC systems DX & chilled water @ N+1.
  • 2.5 MVA of UPS conditioned power @ N+1.
  • Diverse Power Supplies with diesel generator backup.
  • Provision for emergency natural gas powered turbo generators.



The Environmental Impact Of Computers


Crosby works with its technology partners to find new ways to improve the environmental performance of its network.

In redesigning equipment and infrastructure to future proof our business, Crosby takes into account the environmental impact that network assets such as servers, air conditioning and cabinets can have. Examples of this include:

  • Thinner service leads.
  • Noise minimisation devices for server rooms.
  • Slimmer masts for our broadcasting antennas.
  • Wind and solar energy designs to contribute to our overall power use.
  • Reduced power usage during off peak times.

Crosby has procedures, guidelines and standards in place for the installation of all equipment and endeavours to design wireless internet access transmission sites that blend in with their surroundings.

For more details of our efforts to reduce the impact of our operations on the environment, see our Crosby and the Environment page.



Voice Over IP Network


Our VoIP systems are built around Crosby's global network – thereby offering Crosby the cost–effective option of terminating a call to the PSTN network.

In many ways a VoIP call is travelling over the most redundant network known to man: the Internet. Crosby owns and operates an extensive global backbone network including 23 international and domestic gateway switches located throughout Europe, the Americas and the Asia Pacific regions. This network is supported by ownership in over 35 transoceanic fibre optic cable systems, providing the connectivity of Crosby's global network to over 250 countries worldwide. A call on the Crosby VoIP system avoids multiple hops due to our centralised routing and peering relationships, and Crosby routes and monitors a VoIP call in the same fashion as a regular voice call. Each call has multiple termination options that are selected based on quality.


© 1997-2008 Crosby Communications