For marketers
who love technology
Home » , » RSVP-TE: a cheat sheet for Network Architect interviews.

RSVP-TE: a cheat sheet for Network Architect interviews.

This post gives the key take-aways about RSVP-TE. It's an excellent cheat sheet if you are preparing for interviews as a Network Architect or Engineering Program Manager.
  1. RSVP-TE is a signaling protocol in MPLS networks. This means that it can setup a label switched path and reserve ressources for it. That's why RSVP means resource reservation protocol. It's pretty clear name, isn't it?
  2. RSVP has two main messages:
    • PATH, to request the establishment of a reservation
    • RESV, to reserve the resources on the path requested through PATH message.
  3. RSVP is "soft state" that means that the resource reservations must be refreshed periodically otherwise they expire.
  4. The two main messages are complemented with messages to indicate errors (PathErr, ResvErr) and to teardown a reservation faster than with the expiration of the soft state (PathTear, ResvTear)
  5. RSVP defines two handy concepts:
    • flow spec: the QoS level
    • filter spec: the packets to which a flow spec must be applied
If you need to learn more, there is a good old report back from the days where RSVP was standardized, that explains very well RSVP concepts.
An MPLS network (Credit: wikipedia)

About Gilles


Post a Comment