The Source Packet Routing in NetworkinG (SPRING) Working Group is the
home of Segment Routing (SR) over MPLS (SR-MPLS) and over IPv6 (SRv6)
data planes. The SPRING WG is responsible for defining new applications
for, and specifying extensions to, Segment Routing technologies. It also 
serves as a forum to discuss the operational aspects of
deploying and managing SR-MPLS networks. The SRv6
Operations (srv6ops) WG is dedicated to the operational aspects of
deploying and managing SRv6 networks.

The work in the SPRING WG should avoid modification to existing data 
planes that would make them incompatible with existing deployments. 
Existing protocols must be used within existing architectures to 
implement the SPRING function where possible. Any modification or 
extension of existing architectures, data planes, or protocols should 
be carried out in the WGs responsible for them and in coordination 
with the SPRING WG. Alternatively, after agreement among the relevant 
WG chairs and Area Directors, such work may be done in the SPRING WG.

The SPRING WG defines protocol-independent procedures that allow an SR 
node to steer a packet through an SR Policy instantiated as an ordered 
list of instructions called segments without needing per-path state 
information at transit nodes. A network comprising only SR nodes can 
achieve full path control (through loose or strict path specification). 
However, SR nodes must interoperate through loose routing in existing 
networks.

By default, Segment Routing operates within a trusted domain and
requires the enforcement of a strict boundary to prevent Segment
Routing packets from entering the trusted domain [rfc8402]. Some
deployments may involve multiple trusted domains and the use of
cross/inter-domain segments. Documents which deal with such
situations need to include a risk analysis and use mechanisms to
validate that the segment list is provided by an authorized entity
and has not been modified in transit.

The SPRING WG is expected to coordinate and collaborate closely
with the following WGs:

* mpls on the MPLS data plane and associated extensions
* 6man on the IPv6 data plane and associated extensions
* srv6ops on SRv6 operations

As needed, the WG will also collaborate with other WGs to develop
extensions and other SR-related solutions.