Discover How Segment Routing Can Enhance Flexibility in Your Telco Network

With the arrival of 5G, high-speed, low latency transfer of enormous data packets has become a reality. But network operators will seek to simplify the complex processes behind that, especially where 5G shows greatest potential for monetization – for example, in virtual private networks. Operators can do this by implementing Segment Routing (SR), which simplifies data packet forwarding to enable greater efficiency and flexibility.

What is Segment Routing, and how does it work?

As the name suggests, Segment Routing over IPv6 (also known as SRv6, or simply Segment Routing v6) handles individual segments – or steps – in a network. Each segment has a segment identifier (SID), which represented by an IPv6 address to encode instructions for forwarding packets. SRv6 stacks these SIDs (which are contained in a Segment Routing header (SRH), facilitating the creation of optimized and complex routing and greatly simplifying the data packet forwarding process. It is worth noting that there is another implementation of Segment Routing , called SR MPLS. However, this post focuses on what is understood as router segmentation from the SRv6 perspective.

How can Segment Routing be deployed?

Segment Routing has a broad range of applications, including traffic engineering, service function chaining, virtual private network (VPN) services and simplified network operations. Let’s take a look at each in a little more detail.

• Traffic engineering: SRv6 enables precise control over traffic flows, allowing operators to steer traffic through specific paths based on criteria such as bandwidth availability, latency, or policy requirements. This capability is particularly valuable in optimizing the performance of large-scale networks.
• Service function chaining (SFC): SRv6 can be used to implement service function chaining, where packets are directed through a series of network services (such as firewalls, load balancers, or DPI devices) in a specific order. This is achieved by specifying the sequence of service functions as a list of SIDs.
• VPN services: SRv6 supports the creation of scalable and flexible VPN services. By using SIDs to represent different VPN endpoints and paths, operators can simplify the provisioning and management of VPN connections across their networks.
• Simplified network operations: SRv6 reduces the complexity of network operations by eliminating the need for multiple protocols to manage different types of traffic. This simplification leads to easier network management and troubleshooting.

What are the benefits of Segment Routing?

Thanks to the ability to define detailed routing instructions within packet headers, traffic management and optimization becomes more flexible, simpler and more easily scalable. In addition, Segment Routing is integrated by design and will work seamlessly with existing IPv6 infrastructure – meaning it can be implemented gradually. Finally, adopting SRv6 improves efficiency because network resources are managed dynamically, thanks to optimized routing decisions based on real-time network conditions.

Where has SRv6 worked so far?

Many telco operators are conducting pilot projects to evaluate the benefits of SRv6. These projects often focus on use cases such as those outlined above, and are already resulting in positive outcomes. SRv6 has – naturally – found a strong position thanks to the roll-out of 5G networks and the need for operators to be able to deliver VPNs, slicing, and increasingly diverse use cases. Some of the world’s leading equipment vendors (among them, Cisco, Huawei, Juniper and Nokia) have recognized the potential of SRv6 and introduced support for it in their products. Meanwhile the Internet Engineering Task Force (IETF) has been actively working on standardizing SRv6, with several key documents and specifications already published (e.g., RFC 8986).

Conclusion

Like any technological step change, SRv6 comes with certain challenges. Operators wishing to benefit from this development must accept the need to invest in hardware and software to ensure full interoperability and high-level security. Nevertheless, the enhanced flexibility, scalability, and simplicity of SRv6 greatly outweigh the costs involved. With a growing number of use cases, increasing support from vendors and standards bodies, SRv6 certainly has the potential to become a crucial element of modern, efficient, and flexible packet networks.