Your network edge is where your network ends and you connect to the internet. For an ISP, it's how you connect your customers to the outside world; for a content provider, it's how your customers access your content and services. If your business provides an internet based service and you host (or want to host) it from your own equipment, then you need a network edge.

UPDATE: See our blog case study on this topic also.

Open Solutions have built and maintain network edges for companies that want their internet connectivity to just work all of the time but don't have or want the in house resources to build and manage it themselves.

Showreel Player, imag!ne and Cab Call Communications are all examples of companies that we have built and continue to manage a network edge for. In this case study, we'll examine one of these network edges (without mentioning the customer's name).

Overview

Last year, one of our customers decided to move from managed co-location, where a third party owns, manages and sublets rack space and network connectivity, to their own rack. They asked Open Solutions to find a suitable data centre, set-up a network edge and deal with all vendors.

The project hence involved:

• reviewing all available data centres in the chosen location (Dublin, Ireland) and choosing the best from a number of criteria;
• setting up the physical infrastructure: appropriate racks, power distribution units, cable management, etc;
• finding suitable transit providers so as to provide fault tolerant network connectivity and negotiating contracts, pricing and commit levels;
• and the meat of this case study:
  • arranging an AS number and IPv4 and IPv6 allocations from RIPE;
  • purchasing and configuring edge routers;
  • configuring and securing BGP;
• implementing monitoring and alerting systems.

Obtaining AS Number and IP Addresses

One of the more burecratic but essential aspects of setting up an edge network is obtaining an autonomous system (AS) number and IPv4 and IPv6 IP address ranges from RIPE. We have have been through the process a number of times for different customers and can arrange it through the RIPE directly or through LIRs (Local Internet Registries) providing the service.

With the available IPv4 address space becoming scarcer and scarcer, it is of course essential that any new network be dual stacked from the start with IPv6.

Building the Edge

An edge network needs to have at least two routers with at least two providers to be resilient. The network we built for this customer (which was required to have an initial maximum capacity of transiting 1Gbps resiliently) looks like the following:

As the diagram shows, we have chosen three upstream transit providers for the customer (including transit via INEX, Ireland's IXP from one of the providers). We have set up multi-lateral peering with two routers at each provider and with the customer's too.

The routers are each connected to two switches in a fail-over configuration and a high availability gateway is provided to the customer network from the routers using a VRRP protocol. Servers on the customer end are then also connected to both switches in a fail-over bonded configuration ensuring automatic and quick failover.

All the equipment used has two power supplies and each are connected to independant A and B feeds. Hence, outside of the data centre experiencing a total power outage (which has never happened in five years and counting) and operator error, the above configuration will provide 100% network availability.

Monitoring and Alerting

We have built a comprehensive virtual NOC for a number of clients with an additional contract option of our own staff on 24/7 availability. Please see the virtual NOC case study for more information.

Budget Considerations

When we work with our customers, we try and help them plan and build scalable networks and server infrastructures within their budget while keeping their business plan forecasts in mind. Where possible, we advise them to not spend money when they're not making it!

We can build the above network edge in two ways: using expensive branded but dedicated equipment such as Cisco 7301s and Brocade FESX624s; or using commodity servers as routers and lower end L2 managable switches.

We'll help you decide which is best - cheaper isn't always better but often it's the only option!