Internet DRAFT - draft-rekhter-mdrs
draft-rekhter-mdrs
Internet Engineering Task Force H. Jeng
Internet-Draft AT&T
Intended status: Standards Track J. Haas
Expires: July 26, 2014 Y. Rekhter
J. Zhang
Juniper Networks
January 22, 2014
Multicast Distribution Reachability Signaling
draft-rekhter-mdrs-01
Abstract
This document describes a mechanism whereby a subscriber's Internet
service provider may signal in BGP the ability of the subscriber
network to receive content using multicast connectivity. This
mechanism is called Multicast Distribution Reachability Signaling
(MDRS).
Status of this Memo
This Internet-Draft is submitted in full conformance with the
provisions of BCP 78 and BCP 79.
Internet-Drafts are working documents of the Internet Engineering
Task Force (IETF). Note that other groups may also distribute
working documents as Internet-Drafts. The list of current Internet-
Drafts is at http://datatracker.ietf.org/drafts/current/.
Internet-Drafts are draft documents valid for a maximum of six months
and may be updated, replaced, or obsoleted by other documents at any
time. It is inappropriate to use Internet-Drafts as reference
material or to cite them other than as "work in progress."
This Internet-Draft will expire on July 26, 2014.
Copyright Notice
Copyright (c) 2014 IETF Trust and the persons identified as the
document authors. All rights reserved.
This document is subject to BCP 78 and the IETF Trust's Legal
Provisions Relating to IETF Documents
(http://trustee.ietf.org/license-info) in effect on the date of
publication of this document. Please review these documents
carefully, as they describe your rights and restrictions with respect
to this document. Code Components extracted from this document must
Jeng, et al. Expires July 26, 2014 [Page 1]
Internet-Draft MDRS January 2014
include Simplified BSD License text as described in Section 4.e of
the Trust Legal Provisions and are provided without warranty as
described in the Simplified BSD License.
Table of Contents
1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . . 3
2. Specification of Requirements . . . . . . . . . . . . . . . . . 3
2.1. Multicast Distribution Reachability Signaling . . . . . . . 4
3. IANA Considerations . . . . . . . . . . . . . . . . . . . . . . 5
4. Security Considerations . . . . . . . . . . . . . . . . . . . . 5
5. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . . 5
6. Normative References . . . . . . . . . . . . . . . . . . . . . 5
Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . . 5
Jeng, et al. Expires July 26, 2014 [Page 2]
Internet-Draft MDRS January 2014
1. Introduction
Consider a content provider that wants to deliver a particular
content to a set of customers/subscribers, where the provider and the
subscribers are connected by an IP service provider. This content
provider can deliver its content via unicast connectivity or, if
supported by the subscriber network, multicast connectivity. A
mechanism is required to determine if the subscriber network supports
delivery of content to subscribers via multicast connectivity.
This document describes a mechanism whereby the subscriber's Internet
service provider may signal in BGP the ability of the subscriber
network to receive the content using multicast connectivity. This
mechanism is called Multicast Distribution Reachability Signaling
(MDRS).
For the purpose of this document we assume that a content provider
consists of one or more Content Servers, and one or more Content
Distribution Controllers. While this document assumes communication
between Content Servers and Content Distribution Controllers, the
procedures for implementing such communication is outside the scope
of this document.
Content Servers are connected to one or more IP service providers
(ISPs) that can offer both multicast and unicast connectivity service
to the subscribers of the content provider. Content providers use
these ISPs to deliver content to their subscribers.
Subscribers are connected to the Egress Routers (ERs) of the ISP.
Note that the multicast connectivity service provided by the ISP
extends all the way to the ERs. Such service could be provided by
either deploying IP multicast natively, or with some tunneling
mechanism like AMT, or by a combination of both within the ISP.
However, between the ERs and the subscribers there may, or may not be
multicast connectivity.
In the case where a particular subscriber of a given content provider
does not have multicast connectivity to its ER, the content provider
would use IP unicast service provided by the ISP to transmit the
particular content to that subscriber.
2. Specification of Requirements
The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT",
"SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this
document are to be interpreted as described in RFC 2119 [RFC2119].
Jeng, et al. Expires July 26, 2014 [Page 3]
Internet-Draft MDRS January 2014
2.1. Multicast Distribution Reachability Signaling
Multicast distribution reachability signaling is responsible for
giving a content provider, and specifically Content Distribution
Controller(s) of the content provider the information of whether a
particular subscriber of that content provider has multicast
connectivity to an ER of an ISP that the content provider uses for
distributing its content.
This document assumes that each ER can determine the multicast
reachability status for each of the subscriber connected to that ER.
Procedures by which an ER accomplishes this are outside the scope of
this document.
To indicate whether a given ER has multicast reachability to a
subscriber (be that either a native multicast or AMT) this document
uses BGP as follows. An ER originates into IBGP routes for the
subscribers connected to that ER for which the ER has multicast
reachability. These routes are carried using BGP multi-protocol
capabilities [RFC4760] with AFI 1 or 2, and the MCAST-REACH SAFI.
The NLRI field in the MP_REACH_NLRI/MP_UNREACH_NLRI attribute of
these routes contains subscribers' IP addresses encoded as IP address
prefixes. The value of the AFI field in the MP_REACH_NLRI/
MP_UNREACH_NLRI attribute of these routes determines whether
subscribers' addresses are IPv4 or IPv6 (AFI 1 indicates IPv4
addresses, AFI 2 indicates IPv6 addresses).
A Content Distribution Controller, when it receives such routes, uses
them to determine whether the content could be delivered to the
subscribers via the ISP who owns the ERs using the multicast
connectivity service provided by the ISP.
To constrain the flow of BGP routes that carry multicast distribution
reachability information such routes carry a particular Route Target
(RT) Extended Community [RFC4360], and Content Distribution
Controller(s) are provisioned to import routes with such a RT.
RTs carried by routes with AFI 1 and MCAST-REACH SAFI SHOULD NOT be
re-used by routes with any other AFI and/or SAFI. Likewise, RTs
carried by routes with AFI 2 and MCAST-REACH SAFI SHOULD NOT be re-
used by routes with any other AFI and/or SAFI.
To facilitate such constrained distribution of multicast distribution
reachability information one MAY use Constrained Route Distribution
[RFC4684].
Jeng, et al. Expires July 26, 2014 [Page 4]
Internet-Draft MDRS January 2014
3. IANA Considerations
This document defines a new BGP Subsequent Address Family Identifier
(SAFI) value, MCAST-REACH. The authors request assignment of a value
from the First Come, First Served portion of this registry.
4. Security Considerations
TBD
5. Acknowledgements
The authors would like to thank Han Nguyen for his contributions to
this document.
6. Normative References
[RFC2119] Bradner, S., "Key words for use in RFCs to Indicate
Requirement Levels", BCP 14, RFC 2119, March 1997.
[RFC4360] Sangli, S., Tappan, D., and Y. Rekhter, "BGP Extended
Communities Attribute", RFC 4360, February 2006.
[RFC4684] Marques, P., Bonica, R., Fang, L., Martini, L., Raszuk,
R., Patel, K., and J. Guichard, "Constrained Route
Distribution for Border Gateway Protocol/MultiProtocol
Label Switching (BGP/MPLS) Internet Protocol (IP) Virtual
Private Networks (VPNs)", RFC 4684, November 2006.
[RFC4760] Bates, T., Chandra, R., Katz, D., and Y. Rekhter,
"Multiprotocol Extensions for BGP-4", RFC 4760,
January 2007.
Authors' Addresses
Huajin Jeng
AT&T
Phone:
Email: hj2387@att.com
Jeng, et al. Expires July 26, 2014 [Page 5]
Internet-Draft MDRS January 2014
Jeffrey Haas
Juniper Networks
1194 N. Mathida Ave.
Sunnyvale, CA 94089
US
Email: jhaas@juniper.net
Yakov Rekhter
Juniper Networks
1194 N. Mathida Ave.
Sunnyvale, CA 94089
US
Email: yakov@juniper.net
Jeffrey (Zhaohui) Zhang
Juniper Networks
1194 N. Mathida Ave.
Sunnyvale, CA 94089
US
Email: zzhang@juniper.net
Jeng, et al. Expires July 26, 2014 [Page 6]
