--- 1/draft-tarapore-mboned-multicast-cdni-04.txt 2014-03-03 08:14:40.181084416 -0800 +++ 2/draft-tarapore-mboned-multicast-cdni-05.txt 2014-03-03 08:14:40.221085401 -0800 @@ -1,56 +1,56 @@ MBONED Working Group Percy S. Tarapore Internet Draft Robert Sayko Intended status: BCP AT&T -Expires: April 21, 2014 Greg Shepherd +Expires: August 3, 2014 Greg Shepherd Toerless Eckert Cisco Ram Krishnan Brocade - October 21, 2013 + March 3, 2014 Multicasting Applications Across Inter-Domain Peering Points - draft-tarapore-mboned-multicast-cdni-04.txt + draft-tarapore-mboned-multicast-cdni-05.txt 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 April 21, 2014. + This Internet-Draft will expire on August 3, 2014. Copyright Notice - Copyright (c) 2013 IETF Trust and the persons identified as the + 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 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. -IETF I-D Multicasting Applications Across Peering Points October 2013 +IETF I-D Multicasting Applications Across Peering Points February 2014 This document may contain material from IETF Documents or IETF Contributions published or made publicly available before November 10, 2008. The person(s) controlling the copyright in some of this material may not have granted the IETF Trust the right to allow modifications of such material outside the IETF Standards Process. Without obtaining an adequate license from the person(s) controlling the copyright in such materials, this document may not be modified outside the IETF Standards Process, and derivative works of it may not be created outside the IETF Standards Process, except to format @@ -72,38 +72,41 @@ 3. Inter-domain Peering Point Requirements for Multicast..........5 3.1. Native Multicast..........................................5 3.2. Peering Point Enabled with GRE Tunnel.....................6 3.3. Peering Point Enabled with an AMT - Both Domains Multicast Enabled........................................................8 3.4. Peering Point Enabled with an AMT - AD-2 Not Multicast Enabled........................................................9 3.5. AD-2 Not Multicast Enabled - Multiple AMT Tunnels Through AD-2..........................................................11 4. Supporting Functionality......................................13 - 4.1. Network Transport and Security Guidelines................14 - 4.2. Routing Aspects and Related Guidelines...................14 - 4.3. Back Office Functions - Billing and Logging Guidelines...14 - 4.4. Operations - Service Performance and Monitoring Guidelines14 - 4.5. Reliability Models/Service Assurance Guidelines..........14 - 4.6. Provisioning Guidelines..................................14 - 4.7. Client Models............................................14 - 4.8. Addressing Guidelines....................................14 - 5. Security Considerations.......................................15 - 6. IANA Considerations...........................................15 - 7. Conclusions...................................................15 - 8. References....................................................15 + 4.1. Network Interconnection Transport and Security Guidelines14 + 4.2. Routing Aspects and Related Guidelines...................15 + 4.2.1 Native Multicast Routing Aspects..................15 + 4.2.2 GRE Tunnel over Interconnecting Peering Point.....16 + 4.2.3 Routing Aspects with AMT Tunnels.....................16 + 4.3. Back Office Functions - Billing and Logging Guidelines...19 + 4.4. Operations - Service Performance and Monitoring Guidelines19 + 4.5. Reliability Models/Service Assurance Guidelines..........19 + 4.6. Provisioning Guidelines..................................19 + 4.7. Client Models............................................19 + 4.8. Addressing Guidelines....................................19 + 5. Security Considerations.......................................19 -IETF I-D Multicasting Applications Across Peering Points October 2013 +IETF I-D Multicasting Applications Across Peering Points February 2014 - 8.1. Normative References.....................................15 - 8.2. Informative References...................................15 - 9. Acknowledgments...............................................15 + 6. IANA Considerations...........................................20 + 7. Conclusions...................................................20 + 8. References....................................................20 + 8.1. Normative References.....................................20 + 8.2. Informative References...................................20 + 9. Acknowledgments...............................................20 1. Introduction Several types of applications (e.g., live video streaming, software downloads) are well suited for delivery via multicast means. The use of multicast for delivering such applications offers significant savings for utilization of resources in any given administrative domain. End user demand for such applications is growing. Often, this requires transporting such applications across administrative domains via inter-domain peering points. @@ -126,25 +129,25 @@ o Multicast Listener Discovery (MLD) [RFC4604] This document therefore serves the purpose of a "Gap Analysis" exercise for this process. The rectification of any gaps identified - whether they involve protocol extension development or otherwise - is beyond the scope of this document and is for further study. 2. Overview of Inter-domain Multicast Application Transport A multicast-based application delivery scenario is as follows: - o Two independent administrative domains are interconnected via a - peering point. -IETF I-D Multicasting Applications Across Peering Points October 2013 +IETF I-D Multicasting Applications Across Peering Points February 2014 + o Two independent administrative domains are interconnected via a + peering point. o The peering point is either multicast enabled (end-to-end native multicast across the two domains) or it is connected by one of two possible tunnel types: o A Generic Routing Encapsulation (GRE) Tunnel [RFC2784] allowing multicast tunneling across the peering point, or o An Automatic Multicast Tunnel (AMT) [IETF-ID-AMT]. o The application stream originates at a source in Domain 1. o An End User associated with Domain 2 requests the application. It is assumed that the application is suitable for delivery via multicast means (e.g., live steaming of major events, software @@ -169,21 +172,21 @@ Enterprise case. The Use Cases describing various architectural configurations for the multicast distribution along with associated requirements is described in section 3. Unique aspects related to the Enterprise network possibility will be described in this section. A comprehensive list of pertinent information that needs to be exchanged between the two domains to support various functions enabling the application transport is provided in section 4. -IETF I-D Multicasting Applications Across Peering Points October 2013 +IETF I-D Multicasting Applications Across Peering Points February 2014 3. Inter-domain Peering Point Requirements for Multicast The transport of applications using multicast requires that the inter-domain peering point is enabled to support such a process. There are three possible Use Cases for consideration. 3.1. Native Multicast This Use Case involves end-to-end Native Multicast between the two @@ -214,21 +217,21 @@ Advantages of this configuration are: o Most efficient use of bandwidth in both domains o Fewer devices in the path traversed by the multicast stream when compared to unicast transmissions. From the perspective of AD-1, the one disadvantage associated with native multicast into AD-2 instead of individual unicast to every EU -IETF I-D Multicasting Applications Across Peering Points October 2013 +IETF I-D Multicasting Applications Across Peering Points February 2014 in AD-2 is that it does not have the ability to count the number of End Users as well as the transmitted bytes delivered to them. This information is relevant from the perspective of customer billing and operational logs. It is assumed that such data will be collected by the application layer. The application layer mechanisms for generating this information need to be robust enough such that all pertinent requirements for the source provider and the AD operator are satisfactorily met. The specifics of these methods are beyond the scope of this document. @@ -260,21 +263,21 @@ 3.2. Peering Point Enabled with GRE Tunnel The peering point is not native multicast enabled in this Use Case. There is a Generic Routing Encapsulation Tunnel provisioned over the peering point. In this case, the interconnection I1 between AD-1 and AD-2 in Figure 1 is multicast enabled via a Generic Routing Encapsulation Tunnel (GRE) [RFC2784] and encapsulating the multicast protocols across the interface. The routing configuration is basically unchanged: Instead of BGP (SAFI2) across the native IP -IETF I-D Multicasting Applications Across Peering Points October 2013 +IETF I-D Multicasting Applications Across Peering Points February 2014 multicast link between AD-1 and AD-2, BGP (SAFI2) is now run across the GRE tunnel. Advantages of this configuration: o Highly efficient use of bandwidth in both domains although not as efficient as the fully native multicast Use Case. o Fewer devices in the path traversed by the multicast stream @@ -305,21 +308,21 @@ e. GRE tunnels are typically configured manually between peering points to support multicast delivery between domains. f. It is recommended that the GRE tunnel (tunnel server) configuration in the source network is such that it only advertises the routes to the content sources and not to the entire network. This practice will prevent unauthorized delivery of content through the tunnel (e.g., if content is not part of an agreed CDN partnership). -IETF I-D Multicasting Applications Across Peering Points October 2013 +IETF I-D Multicasting Applications Across Peering Points February 2014 3.3. Peering Point Enabled with an AMT - Both Domains Multicast Enabled Both administrative domains in this Use Case are assumed to be native multicast enabled here; however the peering point is not. The peering point is enabled with an Automatic Multicast Tunnel. The basic configuration is depicted in Figure 2. ------------------- ------------------- @@ -350,21 +353,21 @@ implement. Attractive properties of AMT include the following: o Dynamic interconnection between Gateway-Relay pair across the peering point. o Ability to serve clients and servers with differing policies. Disadvantages of this configuration: -IETF I-D Multicasting Applications Across Peering Points October 2013 +IETF I-D Multicasting Applications Across Peering Points February 2014 o Per Use Case 3.1 (AD-2 is native multicast), current router technology cannot count the number of end users or the number bytes transmitted. o Additional devices (AMT Gateway and Relay pairs) may be introduced into the path if these services are not incorporated in the existing routing nodes. o Currently undefined mechanisms to select the AR from the AG @@ -381,21 +384,21 @@ across the peering points once the Gateway in AD-2 receives the (S, G) information from the EU. 3.4. Peering Point Enabled with an AMT - AD-2 Not Multicast Enabled In this AMT Use Case, the second administrative domain AD-2 is not multicast enabled. This implies that the interconnection between AD- 2 and the End User is also not multicast enabled as depicted in Figure 3. -IETF I-D Multicasting Applications Across Peering Points October 2013 +IETF I-D Multicasting Applications Across Peering Points February 2014 ------------------- ------------------- / AD-1 \ / AD-2 \ / (Multicast Enabled) \ / (Non-Multicast \ / \ / Enabled) \ | +----+ | | | | | | +------+ | | | +----+ | | CS |------>| AR |-|---------|-----------------------|-->|EU/G| | | | +------+ | | |I2 +----+ \ +----+ / \ / @@ -427,21 +430,21 @@ o Dynamic interconnection between Gateway-Relay pair across the peering point. o Ability to serve clients and servers with differing policies. o Each AMT tunnel serves as a count for each End User and is also able to track data usage (bytes) delivered to the EU. -IETF I-D Multicasting Applications Across Peering Points October 2013 +IETF I-D Multicasting Applications Across Peering Points February 2014 Disadvantages of this configuration: o Additional devices (AMT Gateway and Relay pairs) are introduced into the transport path. o Assuming multiple peering points between the domains, the EU Gateway needs to be able to find the "correct" AMT Relay in AD- 1. @@ -457,21 +460,21 @@ G) information to the Gateway for this purpose. e. The AMT tunnel capabilities are expected to be sufficient for the purpose of collecting relevant information on the multicast streams delivered to End Users in AD-2. 3.5. AD-2 Not Multicast Enabled - Multiple AMT Tunnels Through AD-2 This is a variation of Use Case 3.4 as follows: -IETF I-D Multicasting Applications Across Peering Points October 2013 +IETF I-D Multicasting Applications Across Peering Points February 2014 ------------------- ------------------- / AD-1 \ / AD-2 \ / (Multicast Enabled) \ / (Non-Multicast \ / \ / Enabled) \ | +----+ | |+--+ +--+ | | | | +------+ | ||AG| |AG| | +----+ | | CS |------>| AR |-|-------->||AR|------------->|AR|-|-->|EU/G| | | | +------+ | I1 ||1 | I2 |2 | |I3 +----+ \ +----+ / \+--+ +--+ / @@ -504,21 +507,21 @@ AD-2. An AMT node comprises co-location of an AMT Gateway and an AMT Relay. One such node is at the AD-2 side of the peering point (node AGAR1 in Figure 4). o Single AMT tunnel established across peering point linking AMT Relay in AD-1 to the AMT Gateway in the AMT node AGAR1 in AD-2. o AMT tunnels linking AMT node AGAR1 at peering point in AD-2 to other AMT nodes located at the edges of AD-2: e.g., AMT tunnel -IETF I-D Multicasting Applications Across Peering Points October 2013 +IETF I-D Multicasting Applications Across Peering Points February 2014 I2 linking AMT Relay in AGAR1 to AMT Gateway in AMT node AGAR2 in Figure 4. o AMT tunnels linking EU device (via Gateway client embedded in device) and AMT Relay in appropriate AMT node at edge of AD-2: e.g., I3 linking EU Gateway in device to AMT Relay in AMT node AGAR2. The advantage for such a chained set of AMT tunnels is that the @@ -550,47 +553,287 @@ 4. Supporting Functionality Supporting functions and related interfaces over the peering point that enable the multicast transport of the application are listed in this section. Critical information parameters that need to be exchanged in support of these functions are enumerated along with guidelines as appropriate. Specific interface functions for consideration are as follows. -IETF I-D Multicasting Applications Across Peering Points October 2013 +IETF I-D Multicasting Applications Across Peering Points February 2014 - 4.1. Network Transport and Security Guidelines + 4.1. Network Interconnection Transport and Security Guidelines + + The term "Network Interconnection Transport" refers to the + interconnection points between the two Administrative Domains. The + following is a representative set of attributes that will need to be + agreed to between the two administrative domains to support + multicast delivery. + + o Number of Peering Points + + o Peering Point Addresses and Locations + + o Connection Type - Dedicated for Multicast delivery or shared + with other services + + o Connection Mode - Direct connectivity between the two AD's or + via another ISP + + o Peering Point Protocol Support - Multicast protocols that will + be used for multicast delivery will need to be supported at + these points. Examples of protocols include eBGP, BGMP, and + MBGP. + + o Bandwidth Allocation - If shared with other services, then + there needs to be a determination of the share of bandwidth + reserved for multicast delivery. + + o QoS Requirements - Delay/latency specifications that need to be + specified in an SLA. + + o AD Roles and Responsibilities - the role played by each AD for + provisioning and maintaining the set of peering points to + support multicast delivery. + + From a security perspective, it is expected that normal/typical + security procedures will be followed by each AD to facilitate + multicast delivery to registered and authenticated end users. Some + security aspects for consideration are: + + o Encryption - Peering point links may be encrypted per agreement + if dedicated for multicast delivery. + + o Security Breach Mitigation Plan - In the event of a security + breach, the two AD's are expected to have a mitigation plan for + shutting down the peering point and directing multicast traffic + +IETF I-D Multicasting Applications Across Peering Points February 2014 + + over alternated peering points. It is also expected that + appropriate information will be shared for the purpose of + securing the identified breach. 4.2. Routing Aspects and Related Guidelines + The main objective for multicast delivery routing is to ensure that + the End User receives the multicast stream from the "most optimal" + source [INF_ATIS_10] which typically: + + o Maximizes the multicast portion of the transport and minimizes + any unicast portion of the delivery, and + + o Minimizes the overall combined network(s) route distance. + + This routing objective applies to both Native and AMT; the actual + methodology of the solution will be different for each. Regardless, + the routing solution is expected to be: + + o Scalable + + o Avoid/minimize new protocol development or modifications, and + + o Be robust enough to achieve high reliability and automatically + adjust to changes/problems in the multicast infrastructure. + + For both Native and AMT environments, having a source as close as + possible to the EU network is most desirable; therefore, in some + cases, an AD may prefer to have multiple sources near different + peering points, but that is entirely an implementation issue. + + 4.2.1 Native Multicast Routing Aspects + + Native multicast simply requires that the Administrative Domains + coordinate and advertise the correct source address(es) at their + network interconnection peering points(i.e., border routers). An + example of multicast delivery via a Native Multicast process across + two administrative Domains is as follows assuming that the + interconnecting peering points are also multicast enabled: + + o Appropriate information is obtained by the EU client who is a + subscriber to AD-2 (see Use Case 3.1). This is usually done via + an appropriate file transfer - this file is typically known as + the manifest file. It contains instructions directing the EU + +IETF I-D Multicasting Applications Across Peering Points February 2014 + + client to launch an appropriate application if necessary, and + also additional information for the application about the source + location and the group (or stream) id in the form of the "S,G" + data. The "S" portion provides the name or IP address of the + source of the multicast stream. The file may also contain + alternate delivery information such as specifying the unicast + address of the stream. + + o The client uses the join message with S,G to join the multicast + stream [RFC2236]. + + To facilitate this process, the two AD's need to do the following: + + o Advertise the source id(s) over the Peering Points + + o Exchange relevant Peering Point information such as Capacity + and Utilization (Other??) + + 4.2.2 GRE Tunnel over Interconnecting Peering Point + + If the interconnecting peering point is not multicast enabled and + both ADs are multicast enabled, then a simple solution is to + provision a GRE tunnel between the two ADs - see Use Case 3.2.2. + The termination points of the tunnel will usually be a network + engineering decision, but generally will be between the border + routers or even between the AD 2 border router and the AD 1 source + (or source access router). The GRE tunnel would allow end-to-end + native multicast or AMT multicast to traverse the interface. + Coordination and advertisement of the source IP is still required. + + The two AD's need to follow the same process as described in 4.2.1 + to facilitate multicast delivery across the Peering Points. + + 4.2.3 Routing Aspects with AMT Tunnels + + Unlike Native (with or without GRE), an AMT Multicast environment is + more complex. It presents a dual layered problem because there are + two criteria that should be simultaneously meet: + + o Find the closest AMT relay to the end-user that also has + multicast connectivity to the content source and + + o Minimize the AMT unicast tunnel distance. + + There are essentially two components to the AMT specification: + +IETF I-D Multicasting Applications Across Peering Points February 2014 + + o AMT Relays: These serve the purpose of tunneling UDP multicast + traffic to the receivers (i.e., End Points). The AMT Relay will + receive the traffic natively from the multicast media source and + will replicate the stream on behalf of the downstream AMT + Gateways, encapsulating the multicast packets into unicast + packets and sending them over the tunnel toward the AMT Gateway. + In addition, the AMT Relay may perform various usage and + activity statistics collection. This results in moving the + replication point closer to the end user, and cuts down on + traffic across the network. Thus, the linear costs of adding + unicast subscribers can be avoided. However, unicast replication + is still required for each requesting endpoint within the + unicast-only network. + + o AMT Gateway (GW): The Gateway will reside on an on End-Point - + this may be a Personal Computer (PC) or a Set Top Box (STB). The + AMT Gateway receives join and leave requests from the + Application via an Application Programming Interface (API). In + this manner, the Gateway allows the endpoint to conduct itself + as a true Multicast End-Point. The AMT Gateway will encapsulate + AMT messages into UDP packets and send them through a tunnel + (across the unicast-only infrastructure) to the AMT Relay. + + The simplest AMT Use Case (section 3.3) involves peering points that + are not multicast enabled between two multicast enabled ADs. An AMT + tunnel is deployed between an AMT Relay on the AD 1 side of the + peering point and an AMT Gateway on the AD 2 side of the peering + point. One advantage to this arrangement is that the tunnel is + established on an as needed basis and need not be a provisioned + element. The two ADs can coordinate and advertise special AMT Relay + Anycast addresses with each other - though they may alternately + decide to simply provision Relay addresses, though this would not be + a optimal solution in terms of scalability. + + Use Cases 3.4 and 3.5 describe more complicated AMT situations as + AD-2 is not multicast enabled. For these cases, the End User device + needs to be able to setup an AMT tunnel in the most optimal manner. + Using an Anycast IP address for AMT Relays allows for all AMT + Gateways to find the "closest" AMT Relay - the nearest edge of the + multicast topology of the source. An example of a basic delivery + via an AMT Multicast process for these two Use Cases is as follows: + + o The manifest file is obtained by the EU client application. This + file contains instructions directing the EU client to an ordered + list of particular destinations to seek the requested stream and, + for multicast, specifies the source location and the group (or + stream) ID in the form of the "S,G" data. The "S" portion provides + +IETF I-D Multicasting Applications Across Peering Points February 2014 + + the URI (name or IP address) of the source of the multicast stream + and the "G" identifies the particular stream originated by that + source. The manifest file may also contain alternate delivery + information such as the address of the unicast form of the content + to be used, for example, if the multicast stream becomes + unavailable. + + o Using the information in the manifest file, and possibly + information provisioned directly in the EU client, a DNS query is + initiated in order to connect the EU client/AMT Gateway to an AMT + Relay. + + o Query results are obtained, and may return an Anycast address or a + specific unicast address of a relay. Multiple relays will + typically exist. The Anycast address is a routable "pseudo- + address" shared among the relays that can gain multicast access to + the source. + + o If a specific IP address unique to a relay was not obtained, the + AMT Gateway then sends a message (e.g., the discovery message) to + the Anycast address such that the network is making the routing + choice of particular relay - e.g., closest relay to the EU. (Note + that in IPv6 there is a specific Anycast format and Anycast is + inherent in IPv6 routing, whereas in IPv4 Anycast is handled via + provisioning in the network. Details are out of scope for this + document.) + + o The contacted AMT Relay then returns its specific unicast IP + address (after which the Anycast address is no longer required). + Variations may exist as well. + + o The AMT Gateway uses that unicast IP address to initiate a three- + way handshake with the AMT Relay. + + o AMT Gateway provides "S,G" to the AMT Relay (embedded in AMT + protocol messages). + + o AMT Relay receives the "S,G" information and uses the S,G to join + the appropriate multicast stream, if it has not already subscribed + to that stream. + + o AMT Relay encapsulates the multicast stream into the tunnel + between the Relay and the Gateway, providing the requested content + to the EU. + +IETF I-D Multicasting Applications Across Peering Points February 2014 + + Note: Further routing discussion on optimal method to find "best AMT + Relay/GW combination" and information exchange between AD's to be + provided. + 4.3. Back Office Functions - Billing and Logging Guidelines 4.4. Operations - Service Performance and Monitoring Guidelines 4.5. Reliability Models/Service Assurance Guidelines 4.6. Provisioning Guidelines In order to find right relay there is a need for a small/light implementation of an AMT DNS in source network. 4.7. Client Models 4.8. Addressing Guidelines -IETF I-D Multicasting Applications Across Peering Points October 2013 - 5. Security Considerations (Include discussion on DRM, AAA, Network Security) +IETF I-D Multicasting Applications Across Peering Points February 2014 + 6. IANA Considerations 7. Conclusions 8. References 8.1. Normative References [RFC2784] D. Farinacci, T. Li, S. Hanks, D. Meyer, P. Traina, "Generic Routing Encapsulation (GRE)", RFC 2784, March 2000 @@ -601,23 +844,27 @@ [RFC4604] H. Holbrook, et al, "Using Internet Group Management Protocol Version 3 (IGMPv3) and Multicast Listener Discovery Protocol Version 2 (MLDv2) for Source Specific Multicast", RFC 4604, August 2006 [RFC4607] H. Holbrook, et al, "Source Specific Multicast", RFC 4607, August 2006 8.2. Informative References + [INF_ATIS_10] "CDN Interconnection Use Cases and Requirements in a + Multi-Party Federation Environment", ATIS Standard A-0200010, + December 2012 + 9. Acknowledgments -IETF I-D Multicasting Applications Across Peering Points October 2013 +IETF I-D Multicasting Applications Across Peering Points February 2014 Authors' Addresses Percy S. Tarapore AT&T Phone: 1-732-420-4172 Email: tarapore@att.com Robert Sayko AT&T