Re: NetJSON and ALTO
Wendy Roome <w.roome <at> alcatel-lucent.com>
2015-09-21 14:50:08 GMT
Thanks for letting the ALTO group know about NetJSON. NetJSON is related
to the proposed ALTO extensions to describe network topology. However, I
think ALTO's needs are sufficiently different, and sufficiently simpler,
that there is no advantage using NetJSON in ALTO.
The proposed ALTO topology extensions give clients a very simple, abstract
view of the network so that clients can determine how much the paths
between endpoints overlap. E.g., suppose a client wants to do parallel
backups to two different cloud servers. If the paths to servers A & B have
many common elements, while the paths to servers A & C do not, the client
would prefer to use A & C.
ALTO could use the NetJSON NetworkGraph sub-schema to describe topology,
but that is considerably more complicated than what we have proposed. For
example, a NetworkGraph has nodes, links that connect nodes, and
descriptions of routing protocols. The front-runner for describing
topology in ALTO is to provide a list of abstract network elements
involved in the path between two endpoint clusters. The elements can be
nodes, links, or combinations of those. A NetJSON NetworkGraph is
considerably more complicated, and much closer to the physical network.
Also, ALTO clients are typically enduser applications with minimal
knowledge of network internals. They want ALTO to hide the details and
give them just what the need, and no more. So few ALTO clients would need
the rest of NetJSON, and forcing them to learn it would just make it
harder to use ALTO. Similarly, I doubt that NetJSON libraries would
simplify ALTO clients; it would just mean a client has to learn how to
turn off features the client will never use.
- Wendy Roome