How can SRv6 and MPLS coexist and interoperate in a hybrid network environment?

1 What is SRv6?

SRv6 stands for Segment Routing over IPv6, a new approach to routing that leverages the IPv6 header to encode a list of segments, or instructions, that a packet must follow to reach its destination. Each segment can represent a node, a link, or a service function in the network. SRv6 simplifies the network architecture by eliminating the need for additional protocols or encapsulations, and enables end-to-end policy enforcement and service chaining.

2 What is MPLS?

MPLS stands for Multiprotocol Label Switching, a widely deployed technology that uses labels to forward packets along predetermined paths in the network. Each label represents a forwarding equivalence class (FEC), or a group of packets that share the same treatment and destination. MPLS routers use label switching to forward packets based on the label value, without inspecting the packet content. MPLS enables traffic engineering, quality of service, and VPN services.

3 Why use SRv6 and MPLS together?

SRv6 and MPLS have different strengths and weaknesses, and can complement each other in different network scenarios. For example, SRv6 can provide more flexibility and scalability in the network edge, where service differentiation and programmability are required. MPLS can provide more efficiency and stability in the network core, where high throughput and low latency are required. By using both technologies together, network operators can optimize their network performance and service delivery, and leverage their existing infrastructure and expertise.

4 How to interconnect SRv6 and MPLS domains?

One of the main challenges of using SRv6 and MPLS together is how to interconnect different domains that use different technologies. There are several possible solutions, depending on the network topology and requirements. One option is to use a border router that can translate between SRv6 and MPLS headers, and vice versa. Another option is to use a tunneling mechanism that can encapsulate SRv6 packets into MPLS packets, and vice versa. A third option is to use a mapping mechanism that can associate SRv6 segments with MPLS labels, and vice versa.

5 How to interoperate SRv6 and MPLS services?

Another challenge of using SRv6 and MPLS together is how to interoperate different services that use different technologies. For example, how to provide end-to-end VPN or QoS services across SRv6 and MPLS domains. There are several possible solutions, depending on the service type and level of integration. One option is to use a service stitching mechanism that can connect SRv6 and MPLS service segments using a common identifier or locator. Another option is to use a service translation mechanism that can convert SRv6 and MPLS service parameters using a common policy or framework.

6 What are some SRv6 deployment scenarios?

SRv6 is still a relatively new technology, and there are not many real-world deployments yet. However, there are some potential scenarios where SRv6 can be beneficial, especially in combination with MPLS. For example, SRv6 can be used to enable network slicing in 5G networks, where different slices can have different performance and security requirements. SRv6 can also be used to enable service function chaining in cloud networks, where different functions can be dynamically inserted or removed from the packet path. SRv6 can also be used to enable network automation and programmability, where different policies and actions can be encoded in the packet header.

7 Here’s what else to consider

This is a space to share examples, stories, or insights that don’t fit into any of the previous sections. What else would you like to add?