Traffic Engineering is one of the most important features
for the WAN networks. Once the TE tunnels are created and forwarding
state is created on the routers, next most important thing is the ability
to map the service prefixes onto appropriate Tunnels.
The service mapping feature needs to be very flexible and
should be able to accommodate variety of end user requirements
and map them to the required behavior on the router.
We have been working on new service mapping architecture in JUNOS which is
flexible and easy to use.The new architecture uses
Transport Class and Transport RIBs.
Transport Class is a set of paths that setisfy certain constraint
or certain SLAs.
Transport RIB is a collection of tunnels that correspond to a
Transport Class
With this new architecture, TE tunnels created using various protocols such as
SR-TE, RSVP, and flex-algo will be placed in corresponding Transport RIBs
for example red.inet.3/blue.inet.3 and so on.
Each Trasport Class has an associated color and the
service prefix also carries the color extended community which automatically
makes the service prefix resolve on the right Transport RIB.
We are considering below requirements for this service mapping architecture
and would be good to get feedback from this group on any additional requirements.
Feedback and suggestions most welcome.
Service Mapping Requirements
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> DSCP based mapping with each DSCP mapping to a Transport Class.
> DSCP based mapping with default mapping to a best-effort transport
> DSCP based mapping with fallback to best-effort when primary
transport tunnel goes down.
> Extended color community based mapping with fallback to best
effort
> Fallback options with specific protocol during migrations
> Falback options to a different Transport Class.
> No Fallback permitted.
> Firewall filter with 5-tuple mapping to a Transport class for
global as well as VPN traffic
More details can be found in below IETF drafts
https://tools.ietf.org/html/draft-hegde-spring-mpls-seamless-sr-01
https://tools.ietf.org/html/draft-kaliraj-idr-bgp-classful-transport-planes-01