ALTO Working Group L. Deng INTERNET-DRAFT China Mobile Intended Status: Standard Track H. Song Expires: Febuary 5, 2015 Huawei S. Kiesel University of Stuttgart July 4, 2014 End Point Properties for Peer Selection draft-deng-alto-p2p-ext-03 Abstract The initial purpose for ALTO protocol is to provide better than random peer selection for p2p networks. The peer selection method does not only depend on the peer location, but also on other properties of the peering node. In this document, we define additional endpoint properties. Status of this Memo This Internet-Draft is submitted to IETF in full conformance with the provisions of BCP 78 and BCP 79. Internet-Drafts are working documents of the Internet Engineering Task Force (IETF), its areas, and its working groups. Note that other groups may also distribute working documents as Internet-Drafts. 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Table of Contents 1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . 3 2 Overview . . . . . . . . . . . . . . . . . . . . . . . . . . . 3 3 Terminology . . . . . . . . . . . . . . . . . . . . . . . . . . 5 4 End Point Extensions . . . . . . . . . . . . . . . . . . . . . 5 4.1 location-related properties . . . . . . . . . . . . . . . . 6 4.2 network-related properties . . . . . . . . . . . . . . . . . 6 4.2.1 Endpoint Property Type: network_access . . . . . . . . . 6 4.2.2 Endpoint Property Type: access_preference . . . . . . . 6 4.3 node-related properties . . . . . . . . . . . . . . . . . . 6 4.3.1 Endpoint Property Type: participating_role . . . . . . . 6 4.3.2 Endpoint Property Type: battery_limited . . . . . . . . 7 4.4 subscription-related properties . . . . . . . . . . . . . . 7 4.4.1 Endpoint Property Type: volume_limited . . . . . . . . . 7 4.4.2 Endpoint Property Type: provisioned_bandwidth . . . . . 7 5 Security Considerations . . . . . . . . . . . . . . . . . . . . 8 6 IANA Considerations . . . . . . . . . . . . . . . . . . . . . . 8 7 Acknowledgements . . . . . . . . . . . . . . . . . . . . . . . 8 8 References . . . . . . . . . . . . . . . . . . . . . . . . . . 9 8.1 Normative References . . . . . . . . . . . . . . . . . . . 9 8.2 Informative References . . . . . . . . . . . . . . . . . . . 9 Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . . 10 Deng, et al. Expires Feb 5, 2015 Page 2 INTERNET DRAFT Jul 4, 2014 1 Introduction The initial purpose for ALTO protocol is to provide better than random peer selection for p2p networks. In this document, we define extended endpoint property extensions that will provide guidance for both p2p and other applications. 2 Overview It is expected that EP properties from the following aspects can be useful for an ALTO client to provide better user experience or avoid performance degradation due to the ignorance of these EP specific information: o location related properties, the information about the geographic location of the end point; o network related properties, the information about the accessing network of the end point, such as the type or configuration of the access network (e.g. 2G/3G/4G, WLAN, DSL, etc.); o node related information, the information about the end point's local features, such as software/hardware configuration and the participating role of the end point (e.g. as a end user, or a CDN server, or a P2P cache, etc.); o subscription related properties, the information about the service provision agreement between the end point's owner (i.e. the subscriber) and the network provider. 2.1 Guidelines and Methodology The most basic principle would be to maintain the EP property set to a minimum, which in turn implies two guidelines: non-redundancy and generality. o Non-redundancy, refers to the guideline that there is no complete coverage between any two properties. o Generality, refers to the guideline that any property defined should be generally applicable to a group of settings. It is not economic to define a property which is bounded to be used only by a single type of applications or for EPs within a single deployment scenarios. In order to make sure that the properties as defined in this document fulfill the above principle and guidelines, we intend to justify each property's definition using the following methodology: Deng, et al. Expires Feb 5, 2015 Page 3 INTERNET DRAFT Jul 4, 2014 Firstly, (usefulness) there should be clear motivation and application scenarios that justify the necessity and value for providing such EP property for peer selection. Secondly, (non-redundancy) to ensure non-redundancy, whenever a new property is defined, it should be analyzed that whether there is any overlap with any pre-defined EP property or can it be deduced from one or multiple pre-defined EP properties. We should avoid defining such redundant properties, but keep the discussion and suggestions for substitution or construction from other defined properties in the document. Thirdly, (case-independency) when designing the concrete information model for the properties, it is suggested to group application/deployment specific information into more general property definition (with different value for different applications/scenarios). 2.2 Privacy considerations Privacy considerations is especially critical to EP property information exposure in ALTO, as they are by definition more stationary information regarding the subscriber of a specific end point. However, each user may have different concerns or sensitive preference over a specific EP property. For example, endpoint property regarding to the service role of the endpoint, such like P2P caching server, or CDN node. Therefore, it may be necessary to provide a mechanism to accommodate this type of individual customization by providing a channel for an end point to explicitly indicate this information based on its own preference. Fortunately, there are generally applicable schemes to be used to address the privacy protection concerns, which may be applicable to a group of EP properties and can be configured by the ISP or the EP subscriber. On the one hand, the privacy concern is unnecessary if the specific endpoint property can also be measured/disclosed in another way. The privacy concern regarding to the accurate information of the endpoint would be alleviated if using relative numbers to rank them. For deployment considerations, it is also possible for each endpoint to make the choice whether to disclose the relative information or not, but an incentive could be used to encourage the disclosure when it is beneficial to the application. Deng, et al. Expires Feb 5, 2015 Page 4 INTERNET DRAFT Jul 4, 2014 On the other hand, access control to sensitive property information may also be used to mitigate the privacy concern of a defined property. Even greater flexibility can be delivered by access control at the discretion of both the network operator and the individual subscriber, which is out of scope for this document. 2.3 Relation with other properties Endpoint information can be extremely dynamic or relatively static. Currently, this specification does not intend to provide any real- time properties such like the available bandwidth from the endpoint [I-D.draft-wu-alto-te-metrics], which is extremely hard to measure and change frequently. But some relatively static properties could be provided, for example, by defining the available bandwidth from the endpoint to be green, yellow and red, such information can be disclosed and be useful when other endpoints consider to connect to it. The basic end point properties as defined in this document, may in turn be used to derive PID properties [I-D.draft-roome-alto-pid- properties] for the corresponding peer group, which can also be used as one of the alternatives for the ALTO serve to directly expose sensitive end point information to distrusted applications. 2.4 Information flow Endpoint properties can be retrieved and aggregated into the ALTO server in two ways, one is from the endpoint itself, and the other is from the service provider which provides network service to the endpoint. An endpoint can discover the ALTO server with ALTO discovery mechanisms, and then setup a communication channel with its ALTO server, and after that the endpoint property from the endpoint itself can be reported. The ALTO server can also be configured to access the Network Management System server or other similar servers provided by the network service provider for the subscription information and etc. 3 Terminology 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]. This document makes use of the ALTO terminology defined in RFC 5693 [RFC5693]. 4 End Point Extensions Deng, et al. Expires Feb 5, 2015 Page 5 INTERNET DRAFT Jul 4, 2014 This document defines new endpoint property types for the ALTO protocol [RFC 7285]. 4.1 location-related properties TBA. 4.2 network-related properties 4.2.1 Endpoint Property Type: network_access One important endpoint property that will impact peer selection is the node access type. If it is a node owned by a home subscriber, the access type can be DSL, FTTB, or FTTH. If it is deployed in a data center, one may prefer to specify a special access type for it, because it is likely to be more robust, and have more network resources than home users. A p2p application may have its own algorithm for peer selection if the node access type information can be provided. The value for this property can be enumerated as "adsl", "ftth", "fttb", "dc", and etc. 4.2.2 Endpoint Property Type: access_preference In case that the end point has its own privacy concerns in revealing its access network type directly to potentially distrusted applications through ALTO, another indirect way of exposing the similar information can be used by "access_preference". The value for this property (defined as integer) can be set by the ISP of the ALTO server, based on its own relative preference to different network access types. A peer with the higher value is more preferable than another peer with the lower value. For example, an ISP could use the following setting for now: 1 = DSL; 10 = FTTB; 12 = FTTH; 50 = DC; and add "100=new_technology", when some new technology better than FTTH appears later. 4.3 node-related properties 4.3.1 Endpoint Property Type: participating_role Different types of end points have different roles or participating policies for a given application, which can be explored in making a better decision when choosing a serving node. For example, as described in [I-D.draft-deng-alto-p2pcache], P2P caching node can Deng, et al. Expires Feb 5, 2015 Page 6 INTERNET DRAFT Jul 4, 2014 also act as p2p peers in a p2p network. If a p2p caching peer is located near the edge of the network, it will reduce the backbone traffic, as well as the uploading traffic. [RFC7069] provides one example of such caching nodes. P2P caching peers are usually expected to be given higher priority than the ordinary peers for serving a content request so as to optimize the network traffic. So it's necessary for the endpoint property to support this indication. In general, the end points which belong to different participating parties (subscriber, ISP, or ICP) within an application's service transaction demonstrate different role/policies. The value for this property can be enumerated as "user", "p2pcache", "super-node", etc. 4.3.2 Endpoint Property Type: battery_limited Another important endpoint property that will impact peer selection is what kind of power supply the peer has. It can be either the electric power or the battery supply. And for most of the time, it is safe to bet that electric power supplied nodes would stay online longer than those battery supplied nodes. And most of the nowadays intelligent equipments are aware of their power supply type. But it is necessary that the power supply of a peer can be queried through some method no matter whether or not it is limited by its battery. The value for this property (defined as a boolean) is either "true" or "false". If the peer in question is actually battery-limited, the value of this property wrt the peer is set to "true". 4.4 subscription-related properties 4.4.1 Endpoint Property Type: volume_limited Many wireless operators offer low-cost plans, which limit the amount of data to be transmitted within a month to some gigabytes. After that they will throttle the subscriber's bandwidth or charge extra money. Hosts with such a tariff, could be tagged by another endpoint property "volume_limited" and should be avoided for peer selection. The value for this property (defined as a boolean) is either "true" or "false". If a peer is constrained by such a subscription plan, the value of this property wrt the peer is set to "true". 4.4.2 Endpoint Property Type: provisioned_bandwidth TBA. Deng, et al. Expires Feb 5, 2015 Page 7 INTERNET DRAFT Jul 4, 2014 5 Security Considerations TBA. 6 IANA Considerations This document adds the following new endpoint property types to the existing registry created by ALTO protocol [RFC7285]. +----------------------+---------------------------------------+ |Identifier |Intended Semantics | +----------------------+---------------------------------------+ |geo-location |TBA. | +----------------------+---------------------------------------+ |participating_role |The type of end point's role, value | |(string) |is enumerated as "user", "p2pcache" | | |"super-node", etc. in ASCII. | +----------------------+---------------------------------------+ |battery_limited |Whether the peer is battery-limited, | |(boolean) |value is "true" or "false". | +----------------------+---------------------------------------+ |network_access |The type of access network of the peer,| |(string) |value is enumerated as "adsl", "ftth", | | |"fttb", "dc", in ASCII. | +----------------------+---------------------------------------+ |link_preference |The relative preference from the ISP's | |(number) |point of view based on the type of | | |network access of the peer, value is | | |a integer. | +----------------------+---------------------------------------+ |volume_limited |Whether the peer's plan is constrained,| |(boolean) |value is "true" or "false". | +----------------------+---------------------------------------+ |provisioned_bandwidth |TBA. | +----------------------+---------------------------------------+ 7 Acknowledgements The authors would like to thank Richard Yang, Michael Scarf, Vijay Gurbani, Reinaldo Penno and Sabine Randriamsy for their review and valuable comments. Deng, et al. Expires Feb 5, 2015 Page 8 INTERNET DRAFT Jul 4, 2014 8 References 8.1 Normative References [RFC2119] Bradner, S., "Key words for use in RFCs to Indicate Requirement Levels", BCP 14, RFC 2119, March 1997. [RFC7285] Alimi, R., Penno, R., and Y. Yang, "ALTO Protocol", RFC7285, March 2014. 8.2 Informative References [I-D.draft-deng-alto-p2pcache] Deng, L., Chen, W., and Q. Yi, "Considerations for ALTO with network-deployed P2P caches", draft-deng-alto-p2pcache-03 (work in progress), February 2014. [RFC7069] Alimi, R., Rahman, A., Kutscher, D., Yang, Y., Song, H., and K. Pentikousis, "DECoupled Application Data Enroute (DECADE)", RFC 7069, November 2013. [I-D.draft-roome-alto-pid-properties] Roome, W. and Yang, R., "PID Property Extension for ALTO Protocol", draft-roome-alto- pid-properties-01 (work in progress), February 2014. [I-D.draft-wu-alto-te-metrics] Wu, Q., Yang, R., Lee, Y., and Randriamasy, S., "ALTO Traffic Engineering Cost Metrics", draft-wu-alto-te-metrics-03 (work-in-progress), June 2014. Deng, et al. Expires Feb 5, 2015 Page 9 INTERNET DRAFT Jul 4, 2014 Authors' Addresses Lingli Deng China Mobile China Email: denglingli@chinamobile.com Haibin Song Huawei China Email: haibin.song@huawei.com Sebastian Kiesel University of Stuttgart, Computing Center Germany Email: ietf-alto@skiesel.de Deng, et al. Expires Feb 5, 2015 Page 10