ALTO Working Group Q. Wu Internet-Draft L. Xia Intended status: Standards Track Huawei Expires: January 30, 2014 July 29, 2013 JSON Format Extensions for Traffic Engineering (TE) performance metrics in the ALTO Information Resource Directory draft-wu-alto-json-te-01 Abstract The base ALTO specification defines two properties for cost metric attribute in the Cost MAP, including 'hopcount' and 'routingcost'. This specification define five new cost metric and one new parameter for Traffic Engineering(TE) performance information in the ALTO Information Resource Directory: Link Delay, Delay Variation, Packet Loss, Residual Bandwidth, Available Bandwidth,linkstate. They can be used either as constraint attribute associated with cost metric attribute 'routingcost' or returned cost metric in the response. 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 January 30, 2014. Copyright Notice Copyright (c) 2013 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 Wu & Xia Expires January 30, 2014 [Page 1] Internet-Draft JSON for ALTO TE July 2013 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. Table of Contents 1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . . 3 2. Conventions used in this document . . . . . . . . . . . . . . 4 3. Cost Map constraint Extensions: . . . . . . . . . . . . . . . 5 4. Cost Metric Extensions: Cost Map attributes . . . . . . . . . 7 4.1. Attribute: linkdelay . . . . . . . . . . . . . . . . . . . 7 4.2. Attribute: linkjitter . . . . . . . . . . . . . . . . . . 9 4.3. Attribute: linkloss . . . . . . . . . . . . . . . . . . . 10 4.4. Attribute: residualbandwidth . . . . . . . . . . . . . . . 11 4.5. Attribute: availablebandwidth . . . . . . . . . . . . . . 13 5. Cost Metric Extensions: Parameters . . . . . . . . . . . . . . 15 5.1. Parameter: linkstate . . . . . . . . . . . . . . . . . . . 15 6. Security Considerations . . . . . . . . . . . . . . . . . . . 17 7. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 18 8. Normative References . . . . . . . . . . . . . . . . . . . . . 19 Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . . 20 Wu & Xia Expires January 30, 2014 [Page 2] Internet-Draft JSON for ALTO TE July 2013 1. Introduction The ALTO protocol [I.D-ietf-alto-protocol] uses a REST-ful design , and encodes its requests and responses using JSON. In ALTO architecture [I.D-ietf-alto-protocol], the ALTO server allows alto information to be gathered from multiple systems(e.g., routing protocol). [I.D-ietf-ospf-te-metric-extensions] describes extensions to OSPF TE called "OSPF TE Metric Extensions", that can be used to distribute network performance information (such as link delay, delay variation, packet loss, residual bandwidth, and available bandwidth). The mechanism defined in [I.D-ietf-ospf-te-metric-extensions]can be used by an ALTO Server to retrieve the necessary performance information supplementing the prefix and network topology data gathered from other sources in the underlying network. In the ALTO Information Resource Directory, Network and Cost Map are two core ALTO Information provided to clients. The TE performance metric can be represented using Cost MAP. The base ALTO specification [I.D-ietf- alto-protocol] defines one typical cost metric attribute for Cost Type in the Cost MAP (i.e.,'routingcost')and uses constraint attribute to list additional constraints to which elements of the Cost Map are related. This specification defines five new cost map attributes and one property associated with these attributes in alto information service: Link Delay, Link Jitter,Packet Loss, Residual Bandwidth, Available Bandwidth,linkstate. These five attribute and one new parameter can be either used as constraint attribute associated with 'routingcost' cost metric attribute or used as returned Cost Map in the response. Wu & Xia Expires January 30, 2014 [Page 3] Internet-Draft JSON for ALTO TE July 2013 2. Conventions used in this document 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 RFC2119 [RFC2119]. Syntax specifications shown here use the augmented Backus-Naur Form (ABNF) as described in [RFC5234], and are specified as in the base JSON specification [RFC4627]. Wu & Xia Expires January 30, 2014 [Page 4] Internet-Draft JSON for ALTO TE July 2013 3. Cost Map constraint Extensions: Section 10.2.2.3 of "ALTO: Application Layer Traffic Optimization Protocol" [I.D-ietf-alto-protocol] states: " object { CostType cost-type; [JSONString constraints<0..*>;] [PIDFilter pids;] } ReqFilteredCostMap; object { PIDName srcs<0..*>; PIDName dsts<0..*>; } PIDFilter; with members: cost-type The CostType (Section 9.7) for the returned costs. The cost-metric and cost-mode fields MUST match one of the supported Cost Types indicated in this resource's capabilities (Section 10.2.2.4). The ALTO Client SHOULD omit the description field, and if present, the ALTO Server MUST ignore the description field. constraints Defines a list of additional constraints on which elements of the Cost Map are returned. This parameter MUST NOT be specified if this resource's capabilities ( Section 10.2.2.4) indicate that constraint support is not available. A constraint contains two entities separated by whitespace: (1) an operator, 'gt' for greater than, 'lt' for less than, 'ge' for greater than or equal to, 'le' for less than or equal to, or 'eq' for equal to; (2) a target cost value. The cost value is a number that MUST be defined in the same units as the Cost Metric indicated by the cost-metric parameter. ALTO Servers SHOULD use at least IEEE 754 double-precision floating point [IEEE.754.2008] to store the cost value, and SHOULD perform internal computations using double- precision floating-point arithmetic. If multiple 'constraint' parameters are specified, they are interpreted as being related to each other with a logical AND. " In the JSON Object of type ReqFilteredCostMap, the constraint attribute is expressed as: " [gt | lt | ge | le | eq ] " Wu & Xia Expires January 30, 2014 [Page 5] Internet-Draft JSON for ALTO TE July 2013 In this specification, the constraint attribute is changed to " [gt | lt | ge | le | eq ] " Accordingly, the constraints definition is changed to: " constraints Defines a list of additional constraints on which elements of the Cost Map are returned. This parameter MUST NOT be specified if this resource's capabilities ( Section 10.2.2.4) indicate that constraint support is not available. A constraint contains three entities separated by whitespace: (1)an cost type is by default cost-type in the JSON Object of type ReqFilteredCostMap. In addition, it could be another cost-type used for the returned cost (2) an operator, 'gt' for greater than, 'lt' for less than, 'ge' for greater than or equal to, 'le' for less than or equal to, or 'eq' for equal to; (3) a target cost value. The cost value is a number that MUST be defined in the same units as the Cost Metric indicated by the cost-metric parameter. ALTO Servers SHOULD use at least IEEE 754 double-precision floating point [IEEE.754.2008] to store the cost value, and SHOULD perform internal computations using double- precision floating-point arithmetic. If multiple 'constraint' parameters are specified, they are interpreted as being related to each other with a logical AND. " Wu & Xia Expires January 30, 2014 [Page 6] Internet-Draft JSON for ALTO TE July 2013 4. Cost Metric Extensions: Cost Map attributes 4.1. Attribute: linkdelay Namespace: Attribute name: linkdelay Purpose: To specify the average link delay between two directly connected neighboring peers in the network. Value type: A single number value containing an integer component that may be prefixed with an optional minus sign, which may be followed by a fraction part and/or an exponent part. Cardinality: *1 Attribute parameters: linkstate Description: This is intended to be a new cost metric. It could be used as a cost metric constraint attribute used together with cost metric attribute 'routingcost' or as returned cost metric in the response. 'routingcost' may also be used with other cost constraint attributes that is used to specify cost constraints. If 'linkdelay' is present, 'routingcost' MUST have at most one 'linkdelay'. Cost mode: A Cost Mode is encoded as a US-ASCII string. The string MUST either have the value 'numerical' or 'ordinal'. Examples 1: POST /endpointcost/lookup HTTP/1.1 Host: alto.example.com Content-Length: 195 Content-Type: application/alto-endpointcostparams+json Accept: application/alto-endpointcost+json,application/alto-error+json { "cost-type": {"cost-mode" : "numerical", "cost-metric" : "linkdelay"}, "endpoints" : { "srcs": [ "ipv4:192.0.2.2" ], "dsts": [ "ipv4:192.0.2.89", "ipv4:198.51.100.34", "ipv4:203.0.113.45" ] } } Wu & Xia Expires January 30, 2014 [Page 7] Internet-Draft JSON for ALTO TE July 2013 HTTP/1.1 200 OK Content-Length: 231 Content-Type: application/alto-endpointcost+json { "meta" : {}, "data" : { "cost-type": {"cost-mode" : "numerical", "cost-metric" : "linkdelay"}, "map" : { "ipv4:192.0.2.2": { "ipv4:192.0.2.89" : 1, "ipv4:198.51.100.34" : 2, "ipv4:203.0.113.45" : 3 } } } } Example 2: POST /endpointcost/lookup HTTP/1.1 Host: alto.example.com Content-Length: 195 Content-Type: application/alto-endpointcostparams+json Accept: application/alto-endpointcost+json,application/alto-error+json { "cost-type": {"cost-mode" : "numerical", "cost-metric" : "routingcost"}, "constraints" : {"linkdelay ls 15"}, "endpoints" : { "srcs": [ "ipv4:192.0.2.2" ], "dsts": [ "ipv4:192.0.2.89", "ipv4:198.51.100.34", "ipv4:203.0.113.45" ] } } HTTP/1.1 200 OK Content-Length: 231 Content-Type: application/alto-endpointcost+json "data": { "cost type": { "cost-mode": "numerical", "cost-metric":"routingcost"}, "constraints" : {"linkdelay"}, Wu & Xia Expires January 30, 2014 [Page 8] Internet-Draft JSON for ALTO TE July 2013 } "map": { "ipv4:192.0.2.2": { "ipv4:192.0.2.89": 0.0[linkdelay eq 0.0], "ipv4:198.51.100.34": 15.0[linkdelay eq 3.0], "ipv4:203.0.113.45": 1.0[linkdelay eq 12.0], } } 4.2. Attribute: linkjitter Namespace: Attribute name: linkjitter Purpose: To specify the average link delay variation between two directly connected neighboring peers. Value type: A single number value containing an integer component that may be prefixed with an optional minus sign, which may be followed by a fraction part and/or an exponent part. Cardinality: *1 Attribute parameters: linkstate Description: This is intended to be a constraint attribute value used together with 'routingcost' cost metric attribute. routingcost' may also be used with other cost constraint attributes that is used to specify cost constraints.If 'linkjitter' is present, 'routingcost' MUST have at most one 'linkjitter'. Cost mode: A Cost Mode is encoded as a US-ASCII string. The string MUST either have the value 'numerical' or 'ordinal'. Examples: POST /endpointcost/lookup HTTP/1.1 Host: alto.example.com Content-Length: 195 Content-Type: application/alto-endpointcostparams+json Accept: application/alto-endpointcost+json,application/alto-error+json { "cost-type": {"cost-mode" : "numerical", "cost-metric" : "routingcost"}, "constraints" : {"linkdelay ls 15","linkjitter ls 8"}, "endpoints" : { "srcs": [ "ipv4:192.0.2.2" ], Wu & Xia Expires January 30, 2014 [Page 9] Internet-Draft JSON for ALTO TE July 2013 "dsts": [ "ipv4:192.0.2.89", "ipv4:198.51.100.34", "ipv4:203.0.113.45" ] } } HTTP/1.1 200 OK Content-Length: 231 Content-Type: application/alto-endpointcost+json "data": { "cost type": { "cost-mode": "numerical", "cost-metric":"routingcost"}, "constraints" : {"linkdelay","linkjitter"} "map": { "ipv4:192.0.2.2": { "ipv4:192.0.2.89": 0[linkdelay eq0.0,linkjitter eq0.00], "ipv4:198.51.100.34": 5[linkdelay eq3.0,linkjitter eq1.0], "ipv4:203.0.113.45":2[linkdelay eq12.0,linkjitter eq5.0], } 4.3. Attribute: linkloss Namespace: Attribute name: linkloss Purpose: To specify a percentage of the total traffic sent over a configurable interval between two directly connected neighboring peers. Value type: A single number value containing an integer component that may be prefixed with an optional minus sign, which may be followed by a fraction part and/or an exponent part. Cardinality: *1 Attribute parameters: linkstate Description: This is intended to be new cost meric. It can be either used as a constraint attribute value used together with 'routingcost' cost metric attribute or useds as returned cost metric. routingcost' may also be used with other cost constraint attributes that is used to specify cost constraints. If 'linkloss' is present, routingcost' MUST have at most one 'linkloss'. Cost mode: A Cost Mode is encoded as a US-ASCII string. Wu & Xia Expires January 30, 2014 [Page 10] Internet-Draft JSON for ALTO TE July 2013 The string MUST either have the value 'numerical' or 'ordinal'. Examples: POST /endpointcost/lookup HTTP/1.1 Host: alto.example.com Content-Length: 195 Content-Type: application/alto-endpointcostparams+json Accept: application/alto-endpointcost+json,application/alto-error+json { "cost-type": {"cost-mode" : "numerical", "cost-metric" : "routingcost"}, "constraints" : {"linkloss le 0.3"} "endpoints" : { "srcs": [ "ipv4:192.0.2.2" ], "dsts": [ "ipv4:192.0.2.89", "ipv4:198.51.100.34", "ipv4:203.0.113.45" ] } } HTTP/1.1 200 OK Content-Length: 231 Content-Type: application/alto-endpointcost+json "data": { "cost type": { "cost-mode": "numerical", "cost-metric":"routingcost"}, "constraints" : {"linkloss"} "map": { "ipv4:192.0.2.2": { "ipv4:192.0.2.89": 0 [linkloss eq0], "ipv4:198.51.100.34": 1 [linkloss eq0.0001], "ipv4:203.0.113.45": 0 [linkloss eq0], } } 4.4. Attribute: residualbandwidth Namespace: Attribute name: residualbandwith Purpose: To specify Maximum Link Bandwidth minus the bandwidth currently allocated between two directly connected neighboring peers. For a link, residual bandwidth is Wu & Xia Expires January 30, 2014 [Page 11] Internet-Draft JSON for ALTO TE July 2013 defined to be Maximum Bandwidth minus the bandwidth currently allocated to RSVP-TE packets. For a bundled link, residual bandwidth is defined to be the sum of the component link residual bandwidths. Value type: A single number value containing an integer component that may be prefixed with an optional minus sign, which may be followed by a fraction part and/or an exponent part. Cardinality: *1 Attribute parameters: linkstate Description: This is intended to be a new cost metric. It could be either used as a constraint attribute value used together with 'routing cost' cost metric attribute or as returned cost metric in the response.'routingcost' may also be used with other cost constraint attributes that is used to specify cost constraints.If 'residualbw' is present, 'routingcost' MUST have at most one 'residualbw'. Cost mode: A Cost Mode is encoded as a US-ASCII string. The string MUST either have the value 'numerical' or 'ordinal'. Examples: POST /endpointcost/lookup HTTP/1.1 Host: alto.example.com Content-Length: 195 Content-Type: application/alto-endpointcostparams+json Accept: application/alto-endpointcost+json,application/alto-error+json { "cost-type": {"cost-mode" : "numerical", "cost-metric" : "routingcost"}, "constraints" : {"residbw ls 15"}, "endpoints" : { "srcs": [ "ipv4:192.0.2.2" ], "dsts": [ "ipv4:192.0.2.89", "ipv4:198.51.100.34", "ipv4:203.0.113.45" ] } } HTTP/1.1 200 OK Content-Length: 231 Content-Type: application/alto-endpointcost+json Wu & Xia Expires January 30, 2014 [Page 12] Internet-Draft JSON for ALTO TE July 2013 "data": { "cost type": { "cost-mode": "numerical", "cost-metric":"routingcost"}, "constraints" : {"residbw"} "map": { "ipv4:192.0.2.2": { "ipv4:192.0.2.89": 0[residbw eq0.000000], "ipv4:198.51.100.34": 5[residbw eq12.5], "ipv4:203.0.113.45":2[residbw eq5.9], } } 4.5. Attribute: availablebandwidth Namespace: Attribute name: availablebandwith Purpose: To specify the available bandwidth on a link between two directly connected neighboring peers. For a link, available bandwidth is defined to be residual bandwidth minus the measured bandwidth used for the actual forwarding of non- RSVP-TE packets. For a bundled link, available bandwidth is defined to be the sum of the component link available bandwidths. Value type: A single number value containing an integer component that may be prefixed with an optional minus sign, which may be followed by a fraction part and/or an exponent part. Cardinality: *1 Attribute parameters: linkstate Description: This is intended to be a new cost metric. It can be either used as constraint attribute value used together with 'routing cost' cost metric attribute or used as returned cost metric in the response.'routingcost' may also be used with other cost constraint attributes that is used to specify cost constraints.If 'availablebw' is present, 'routingcost' MUST have at most one 'availablebw'. Cost mode: A Cost Mode is encoded as a US-ASCII string. The string MUST either have the value 'numerical' or 'ordinal'. Examples: Wu & Xia Expires January 30, 2014 [Page 13] Internet-Draft JSON for ALTO TE July 2013 POST /endpointcost/lookup HTTP/1.1 Host: alto.example.com Content-Length: 195 Content-Type: application/alto-endpointcostparams+json Accept: application/alto-endpointcost+json,application/alto-error+json { "cost-type": {"cost-mode" : "numerical", "cost-metric" : "routingcost"}, "constraints" : {"availablebw ls 15"}, "endpoints" : { "srcs": [ "ipv4:192.0.2.2" ], "dsts": [ "ipv4:192.0.2.89", "ipv4:198.51.100.34", "ipv4:203.0.113.45" ] } } HTTP/1.1 200 OK Content-Length: 231 Content-Type: application/alto-endpointcost+json "data": { "cost type": { "cost-mode": "numerical", "cost-metric":"routingcost"}, "constraints" : {"residbw","availbw"} "endpoints": { "srcs": [ "ipv4:192.0.2.2" ], "dsts": [ "ipv4:192.0.2.89", "ipv4:198.51.100.34", "ipv4:203.0.113.45" ] } "map": { "ipv4:192.0.2.2": { "ipv4:192.0.2.89": 0[residbw eq0,availbw eq0], "ipv4:198.51.100.34": 0[residbw eq12.5,availbw eq10.5], "ipv4:203.0.113.45":0[residbw eq5.9,availbw eq3.9], } } Wu & Xia Expires January 30, 2014 [Page 14] Internet-Draft JSON for ALTO TE July 2013 5. Cost Metric Extensions: Parameters The following sections define Parameters used within cost metrics Definitions in the section 3. 5.1. Parameter: linkstate Namespace: Parameter name: linkstate Purpose: Used in a multi-valued property to indicate whether it is steady state link performance. Description: When a property is multi-valued, LINKSTATE can be used to construct a steady state Performance topology for initial tunnel path computation, or to verify alternative failover paths. The LINSTATE is set when the measured value of this parameter exceeds its configured maximum threshold. The LINKSTATE is cleared when the measured value falls below its configured threshold. LINKSTATE should be used together with Cost metric we defined in the section 3. Cost Metrics prefixed with 'lss:' are reserved for cost metric that is not steady state link performance. Cost Metrics without prefix 'lss:' indicate the cost metrics are steady state link performace. Examples: POST /endpointcost/lookup HTTP/1.1 Host: alto.example.com Content-Length: 195 Content-Type: application/alto-endpointcostparams+json Accept: application/alto-endpointcost+json,application/alto-error+json { "cost-type": {"cost-mode" : "numerical", "cost-metric" : "routingcost"}, "constraints" : {"linkdelay ls 15"}, "endpoints" : { "srcs": [ "ipv4:192.0.2.2" ], "dsts": [ "ipv4:192.0.2.89", "ipv4:198.51.100.34", "ipv4:203.0.113.45" ] Wu & Xia Expires January 30, 2014 [Page 15] Internet-Draft JSON for ALTO TE July 2013 } } HTTP/1.1 200 OK Content-Length: 231 Content-Type: application/alto-endpointcost+json "data": { "cost type":{ "cost-mode": "numerical", "cost-metric":"routingcost"} "constraints": {"linkdelay"} "map": { "ipv4:192.0.2.2": { "ipv4:192.0.2.89": 0.0[lss:linkdelay eq 100], } } Wu & Xia Expires January 30, 2014 [Page 16] Internet-Draft JSON for ALTO TE July 2013 6. Security Considerations The properties defined in this document present no security considerations beyond those in Section 14 of the base ALTO specification [draft-ietf-alto-protocol]. Wu & Xia Expires January 30, 2014 [Page 17] Internet-Draft JSON for ALTO TE July 2013 7. IANA Considerations IANA has added the following entries to the ALTO cost map Properties registry, defined in Section 3 of [RFCXXX]. +-----------+--------------+------------------------+ | Namespace | Property | Reference | +-----------+--------------+------------------------+ | | linkdelay | [RFCxxxx], Section 3.1 | | | linkjitter | [RFCxxxx], Section 3.2 | | | linkloss | [RFCxxxx], Section 3.3 | | | residbw | [RFCxxxx], Section 3.4 | | | availbw | [RFCxxxx], Section 3.5 | +-----------+--------------+------------------------+ IANA has added the following entries to the " ALTO cost map Parameters" registry, defined in [RFCxxxx] Section 4.1. +-------+------------------------+------------------------+ | Name- | | | | space | Parameter | Reference | +-------+------------------------+------------------------+ | | LINKSTATE | [RFCxxxx], Section 4.1 | +-------+------------------------+------------------------+ Wu & Xia Expires January 30, 2014 [Page 18] Internet-Draft JSON for ALTO TE July 2013 8. Normative References [ALTO] Alimi, R., "ALTO Protocol", ID draft-ietf-alto-protocol-16, May 2013. [OSPF] Giacalone, S., "OSPF Traffic Engineering (TE) Metric Extensions", ID draft-ietf-ospf-te-metric-extensions-04, June 2013. [RFC2119] Bradner, S., "Key words for use in RFCs to Indicate Requirement Levels", March 1997. [RFC4627] Crockford, D., "The application/json Media Type for JavaScript Object Notation (JSON)", RFC 4627, July 2006. [RFC5234] Crocker, D., "Augmented BNF for Syntax Specifications: ABNF", RFC 5234, January 2008. Wu & Xia Expires January 30, 2014 [Page 19] Internet-Draft JSON for ALTO TE July 2013 Authors' Addresses Qin Wu Huawei 101 Software Avenue, Yuhua District Nanjing, Jiangsu 210012 China Email: sunseawq@huawei.com Liang Xia Huawei 101 Software Avenue, Yuhua District Nanjing, Jiangsu 210012 China Email: frank.xialiang@huawei.com Wu & Xia Expires January 30, 2014 [Page 20]