The Service Provider and large enterprise networks have been affected by a set of disruptive technologies in the recent years with increasingly complex traffic volumes, mix, and flows. The intersection of telecommunications, Internet and IT networking paradigms combined with advances in hardware and software technologies has created an environment that is ripe for rapid innovations and disruptions.
‘Software defined networking’ (SDN) and ‘network function virtualization’ (NFV) are two promising concepts developed in the telecommunications industry with the goal of enabling flexible network deployment and more dynamic operations. In addition, advances in hardware technologies, software technologies, cloud computing, and the advent of DevOps have led to agile software development in the IT and web application industries. These same methodologies can be used to enable the transformation of the telecommunications network to simplify operations, administration, maintenance and provisioning and also to lay the network foundation for new access technologies (e.g., 5G).
The following are key features of the network based on SDN and NFV:
- Separation of control and data plane;
- Virtualization of network functions;
- Programmatic control of network;
- Programmatic control of computational resources using orchestration;
- Standards based configuration protocols;
- Automated resource orchestration in response to application/function needs
Combining these techniques facilitates dynamic adaptation of the network based on the application, increases operational flexibility, and simplifies service development.
‘BGP free’ Core: BGP provides external reachability in transit networks but do all IP/MPLS routers really require this external routing information? If all the transit routers forward packets based on an IP lookup, then the answer is clearly yes. But since the P/LSR routers in an MPLS network forward packets based on a label lookup, then why do they still need to run BGP and maintain all that external routing state? The Internet IPv4 routing table is massive. The IPv6 routing table is relatively small in comparison but it continues to grow as IPv6 is becoming more widely deployed. It’s difficult to predict how many IPv4 or IPv6 routes there will be in the Internet in 2 years, let alone in 5 or more years.
To address some of the challenges in density, performance and capacity, a simplified “super-core” network architecture has been developing over the recent years. The definition of “super-core” may vary slightly depending on who you ask, but in general it reflects an “inner” core network that is architected differently than the rest of the network. Our general definition of a super-core architecture is based on a few different factors; one being the high density and scalability requirements of the super-core router and the other being a reduced control plane and route table capacity requirement of the super-core router. A reduced route table capacity requirement is achieved by removing the requirement to run BGP on these super-core routers. Since LSRs in the core network only forward packets by examining the MPLS label information, they do not look into the IP packet header. So, these routers do not need to know about all the external Internet routing information that is distributed by BGP; hence, they no longer need to run BGP. This can be a beautiful thing! One definition of such a network is a “BGP-free core” network. In this type of network, BGP only runs at the edges of the network where external Internet routing information is required.
IP Offload: Another trend we are seeing in the more progressive SPs is what we are calling an “IP Offload” architecture. This is basically where “commodity” Internet transit traffic is forwarded over a simplified, higher capacity yet cost efficient network; which runs in parallel to the traditional multi-service MPLS backbone. What some providers are discovering is that while Internet transit traffic continues to grow exponentially, the revenues associated with this traffic are not keeping pace. In addition, enterprise VPN and other services are not growing as rapidly and this is where a large portion of the SPs revenues are derived. This presents a dilemma for the SP; to continue to invest in and upgrade the capacity of the multi-service MPLS network (which carries both Internet and enterprise VPN traffic) or to do something different.
One answer is to move the high growth Internet traffic to a simpler and more cost effective, higher capacity core network while maintaining the enterprise VPN and other services on the traditional MPLS network. Since the traffic that is being moved to this IP Offload network is Internet transit traffic (eg. Public facing), we can refer to this as a “Public IP Offload” strategy.
Our consultants have extensive experience and expertise with state-of-the-art Multi Service Core/Broadband concepts:
Service Provider and large enterprise network Design
Advanced routing (BGP, OSPF, ISIS)MPLS and related technologies (RSVP, LDP, Traffic Engineering, MPLS restoration using Fast Reroute), Layer2/3 MPLS VPNs, VPLS, EVPNs, Seamless MPLS and BGP Labeled Unicast (BGP-LU), Metro Ethernet design, Video and Voice delivery over IP/MPLS networks
Advanced Multicast Architectures including next-generation multicast VPNs (NG MVPNs)
Subscriber Management and BRAS IPv4/IPv6 Design
IPv6 design and migration planning
Automation Tool development and design
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