Layer-2 WAN services
MPLS provides us with a packet-forwarding mechanism to underpin the NGN – but we still need to build customer services on top of this layer. We need to provide a secure, private environment for each customer.
For many years most carriers have offered only Layer-3 VPNs as a service. Also called IP VPNs, these type of VPN service are now so ubiquitous in the industry that they have become known simply as “MPLS”. But given our focus on enterprise customers, and our business benefit agnostic approach, it would have been rather unimaginative for us to settle for Layer-3 WAN services when we have the ability to go far beyond this.
We continue to build WAN service offerings around Layer-3 VPNs, but have chosen to focus on Layer-2 VPNs of late. This dramatically increases what we can achieve for the customer technically, while also making it much faster and easier to support, thereby reducing cost and improving the customer experience.
Complete IP Solutions have offered Layer-2 VPNs since day one, we haven’t had to drag our heels in the marketplace or play down the benefits in order to extend the life of old networks, or preserve revenue from an existing Layer-3 VPN customer base.
Layer-2 point-to-point (EPL) and multipoint-to-multipoint (VPLS) services are the components with which we build all our bespoke solutions. Here is how these services differ from “MPLS” IP VPNs in terms of features:
Technical feature comparison
|Feature||Layer-3 WAN||Layer-2 WAN|
|Multipoint to multipoint connectivity.||YES||YES|
|Carry IP packets.||YES||YES|
|Carry non IP traffic: IPX, UDLD, CDP LLDP, RSTP etc.||NO||YES|
|The customer can carry their own VLANs within the service||NO||YES|
|Service has Multicast support||NO||YES|
|IP subnets extendable over multiple geographical sites; Layer-2 adjacency for VMware.||NO||YES|
|Ability to run any interior gateway protocol between customer sites, including OSPF or EIGRP.||NO||YES|
|Ability for customer to take complete control of their own Layer-3 environment.||NO||YES|
Customer Choice and Control
If it suits our customers, they have the ability to take complete control of their own network routing and security. It’s like we have just given them a private, virtual Layer-2 switch in our network.
Alternatively we can provide a fully managed routed setup. Within these two extremes there is a range of possibilities in terms of hybrid managed/unmanaged solutions.
Failover between redundant access circuits can be achieved much more quickly with Layer-2 services because of the control we have. Depending on the solution and requirements, this failover can be achieved at Layer-2 or Layer-3.
MPLS IP VPNS use BGP as the routing protocol, which is an EGP (Exterior Gateway Protocol) designed for policy control on the Internet, rather than speed and efficiency in private networks.
Since VPLS is just a switch we do not have to do that. We or the customer themselves can implement any IGP (Interior Gateway Protocol). If we use OSPF we can achieve failover in seconds rather than minutes, making minimum impact on the end users.
Delivering unique WAN Deployments with Layer 2 adjacency
Since a single LAN segment can extend to any location disaster recovery and highly available clusters can be built across multiple datacentres. Remember, we can carry any Ethernet traffic. Firewalls or servers can exist in different parts of the world, but think they are sitting in the same rack.
We can run a group protocol such as HSRP or VRRP within the WAN. This allows two routers, firewalls or load balancers to present a single, shared virtual IP address as a gateway for the rest of the network. There are many applications for this. Combined with our virtual firewall product, this functionality delivers transparent, resilient Internet. Meanwhile, our ecommerce customers can use a VPLS to host firewalls and load balancers in the cloud and distribute traffic across multiple datacentres.
Our Layer 2 services go hand in hand with desktop/server virtualisation and datacentre automation. VMwares Cloud Operating System VSphere, including the VMotion feature, officially requires Layer-2 continuity between interfaces. Only Layer-2 WAN services can connect datacentres in this way.
Summary and Conclusion
From inception we made a decision that we should concentrate on offering the optimum connectivity infrastructure choices, for all the reasons and business benefits outlined above. This decision has enabled customers to achieve everything that can be done with Layer-3 services, but then go far beyond this if they choose a VPLS network.
The most important benefits we wanted to bring to customers were cost effectiveness, speed, resilience and security, ease of support and manageability. We wanted to offer networks flexible and powerful enough to build any solution from a single site Internet connection, right up to global WANs and datacentre projects.
The NGN Carrier Ethernet platform is virtualised and intelligent in the core. This network carries thousands of logical customer connections and WAN environments. The network is viewed as a “cloud”, with its Service Creation Platform, its secure and distinct logical network environments, its portal-based control panel (APM), and its on-demand and elastic nature in terms of bandwidth and QoS.
During the last decade the entire IT industry has been moving through an historic period of transition to a new cloud based model, with a new economic advantage; a move towards the consumption of IT resources as a service rather than a physical product. But this transition can only occur when the right connectivity is available. Cost effective, low latency, high bandwidth Ethernet is what is enabling this transition in the enterprise.
So now the same carefully designed and managed Layer-2 network and platform built for enterprise connectivity is providing the essential “smart wires” required to build resilient, distributed utility computing and storage. This capability will mark the next phase of what Complete IP Solutions delivers to our customers in their transition to cloud services.