> On 03/06/2014 10:00 AM, Adrian Farrel wrote: > > I am disconcerted by even the mention of RIB. Is the proposal to > build a "P2P > > layer RIB" or is the proposal to start to include network layer > information in > > ALTO? > > Adrian: The intent it to include some "abstract" network layer > information in ALTO, more than is now available through the network > map and cost map constructs, but most certainly not raw topology or RIB > data.
As original author of this text, I have to back what Vijay explained: I wrote that text to explain my understanding of how ALTO differs to other IETF work, e.g., I2RS or possibly PCE. An ALTO client needs network topology information to perform an intelligent endpoint selection, in particular if the ALTO client is an IT software application that is not tightly integrated into network operation (e.g., a CDN mgmt system, a cloud orchestrator, ...). This probably means: - A ALTO server operator may not be interested in exposing the full routing topology, including all internal IGP/BGP configuration details, to such an IT application. Specifically, the ALTO client may not be an application operated by the network operations team of an ISP, i.e., it is not an NMS plugin or something similar. Therefore, for privacy, robustness, and other reasons (e.g., corporate policies), the ALTO server would only provide an abstract, orchestrated view of what matters for a given client. - In many use cases, an ALTO client is developed by IT developers without a full understanding of routing protocol details. Therefore, it is up to the ALTO server to offer a representation that IT developers can understand without routing protocol expertise. In my experience, the simplicity of ALTO is a key value proposition for such developers. - draft-ietf-alto-deployments Section 3.2.1 explains how an ALTO server can get access to network information. My current understanding is that use of BGP-LS, I2RS or other direct interfaces into network elements would possibly require that the ALTO server to understands routing protocol details (there are other alternatives). Possibly it will have to correlate such data with other data sources. But it will be up to the policies in the ALTO server to extract and create an abstract topology representation out of this. Obviously, ALTO should be flexible to enable the server to express what it wants to expose. In summary, in my view, an ALTO server exposes a filtered network topology that removes all internal, operational network data (including RIB details) that does not matter to its clients. Michael _______________________________________________ alto mailing list [email protected] https://www.ietf.org/mailman/listinfo/alto
