Internet DRAFT - draft-contreras-alto-bgp-communities

draft-contreras-alto-bgp-communities







ALTO WG                                                    LM. Contreras
Internet-Draft                                                Telefonica
Intended status: Informational                             July 13, 2020
Expires: January 14, 2021


                Extending ALTO by using BGP Communities
                draft-contreras-alto-bgp-communities-00

Abstract

   This memo introduces the proposal of extending ALTO by using BGP
   Communities as PIDs.

Status of This Memo

   This Internet-Draft is submitted in full conformance with the
   provisions of BCP 78 and BCP 79.

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   This Internet-Draft will expire on January 14, 2021.

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Table of Contents

   1.  Introduction  . . . . . . . . . . . . . . . . . . . . . . . .   2
   2.  BGP Communities . . . . . . . . . . . . . . . . . . . . . . .   2
   3.  Extending ALTO with BGP communities . . . . . . . . . . . . .   3
   4.  BGP Community representation in ALTO  . . . . . . . . . . . .   3
   5.  Security Considerations . . . . . . . . . . . . . . . . . . .   3
   6.  IANA Considerations . . . . . . . . . . . . . . . . . . . . .   3
   7.  References  . . . . . . . . . . . . . . . . . . . . . . . . .   3
   Author's Address  . . . . . . . . . . . . . . . . . . . . . . . .   4

1.  Introduction

   The Provider-defined Identifiers (PIDs) in the ALTO protocol
   [RFC7285] provide an indirect and network-agnostic way to specify an
   aggregation of network endpoints, that grouped creates a network map.
   Network end-points sharing a common PID are expected to receive
   similar treatment on the decisions assisted by ALTO.

   With the same idea of grouping of destinations, the concept of BGP
   Communities [RFC1997] was developed to apply a common routing
   decision to a number of destinations based on the identity of a
   group.  Since BGP communities are widely configured in real
   operational networks, this document propose an extension to [RFC7285]
   by defining a new type of PID based on the BGP community concept.

2.  BGP Communities

   A BGP Community is a BGP attribute which is used to group
   destinations

   The BGP Communities are represented as an integer number of 32 bit.
   It is typically written as the combination of two integer numbers of
   16 bit separated by colon.  The first number is usually the
   Autonomous System (AS) number, while the second one is determined by
   the service provider according to some internal logic.

   The IP prefixes can be part of distinct BGP Communities, with
   different purposes, typically for influencing the traffic reaching
   the particular prefizes of a community.

   The BGP Community attribute is useful for applying polcies of
   applicability to a certain set of prefixes, grouped as a community
   for some reason at the criteria of the service provider.







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3.  Extending ALTO with BGP communities

   Network operators use extensively BGP Communities as a mean of
   putting together some destinations (i.e., IP prefixes) for different
   purposes Traditionally they are used by administratively-defined
   filters for applying policies, thus Influencing the behavior of the
   traffic towards the associated destinations.

   On the other hand, the ALTO protocol based on IP prefixes.  When
   cosnidering queries to IP prefixes, it could be the case that those
   queries apply for IP addresses associated to the same topological
   element.  This is for instance the case of aggregations node in the
   Network (such as BNG or PGW for example) which have associated a
   number of IP prefixes (that can evolve along the time).  The same
   response will be obtained from ALTO server for all the prefixes
   associated with such a node since the topological information is
   essentially the same.

   For assisting on an efficient usage of ALTO resources in this kind of
   situations, the usage of BGP Communities can simplify the process by
   reducing the number of queries to ALTO server, but also by smoothly
   absorbing the modification of prefixes for a given aggregation node.

4.  BGP Community representation in ALTO

   To be done.

5.  Security Considerations

   To be done.

6.  IANA Considerations

   This draft does not include any IANA considerations

7.  References

   [RFC1997]  Chandra, R., Traina, P., and T. Li, "BGP Communities
              Attribute", RFC 1997, DOI 10.17487/RFC1997, August 1996,
              <https://www.rfc-editor.org/info/rfc1997>.

   [RFC7285]  Alimi, R., Ed., Penno, R., Ed., Yang, Y., Ed., Kiesel, S.,
              Previdi, S., Roome, W., Shalunov, S., and R. Woundy,
              "Application-Layer Traffic Optimization (ALTO) Protocol",
              RFC 7285, DOI 10.17487/RFC7285, September 2014,
              <https://www.rfc-editor.org/info/rfc7285>.





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Author's Address

   Luis M. Contreras
   Telefonica
   Ronda de la Comunicacion, s/n
   Sur-3 building, 3rd floor
   Madrid  28050
   Spain

   Email: luismiguel.contrerasmurillo@telefonica.com
   URI:   http://lmcontreras.com/








































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