ALTO Working Group Q. Wu
Internet-Draft Huawei
Intended status: Standards Track Y. Yang
Expires: August 18, 2014 Yale University
Y. Lee
D. Dhody
Huawei
S. Randriamasy
Alcatel-Lucent
February 14, 2014
ALTO Traffic Engineering Cost Metrics
draft-wu-alto-te-metrics-01
Abstract
Cost Metric is a basic concept in Application-Layer Traffic
Optimization (ALTO). It is used in both the Cost Map Service and the
Endpoint Cost Service. Future extensions to ALTO may also use Cost
Metric.
Different applications may benefit from different Cost Metrics. For
example, a Resource Consumer may prefer Resource Providers that have
low delay to the Resource Consumer. However the base ALTO protocol
[ALTO] has defined only a single cost metric, i.e., the generic
"routingcost" metric (Sec. 14.2 of ALTO base specification [ALTO]).
In this document, we define eleven Cost Metrics, derived from OSPF-TE
and ISIS-TE, to measure network delay, jitter, packet loss, hop
count, and bandwidth. The metrics defined in this document provide a
relatively comprehensive set of Cost Metrics for ALTO focusing on
traffic engineering (TE). Additional Cost Metrics such as financial
cost metrics may be defined in other documents.
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
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material or to cite them other than as "work in progress."
This Internet-Draft will expire on August 18, 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
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.
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Table of Contents
1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . . 4
2. Conventions used in this document . . . . . . . . . . . . . . 5
3. Metric: Delay . . . . . . . . . . . . . . . . . . . . . . . . 6
4. Metric: Delayjitter . . . . . . . . . . . . . . . . . . . . . 9
5. Metric: Pktloss . . . . . . . . . . . . . . . . . . . . . . . 12
6. Metric: Hopcount . . . . . . . . . . . . . . . . . . . . . . . 15
7. Metric: Bandwidth . . . . . . . . . . . . . . . . . . . . . . 16
8. Metric: Maximum Bandwidth . . . . . . . . . . . . . . . . . . 18
9. Metric: Maximum Reserved Bandwdith . . . . . . . . . . . . . . 21
10. Metric: Unavailable Reserved Bandwidth . . . . . . . . . . . . 24
11. Metric: Residue Bandwidth . . . . . . . . . . . . . . . . . . 27
12. Metric: Available Bandwidth . . . . . . . . . . . . . . . . . 30
13. Metric: Utilized Bandwidth . . . . . . . . . . . . . . . . . . 33
14. Security Considerations . . . . . . . . . . . . . . . . . . . 36
15. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 37
16. References . . . . . . . . . . . . . . . . . . . . . . . . . . 38
16.1. Normative References . . . . . . . . . . . . . . . . . . 38
16.2. Informative References . . . . . . . . . . . . . . . . . 38
Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . . 39
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1. Introduction
Cost Metric is a basic concept in Application-Layer Traffic
Optimization (ALTO). It is used in both the Cost Map Service and the
Endpoint Cost Service. In particular, applications may benefit from
knowing network performance measured on several Cost Metrics. For
example, a more delay sensitive application may focus on latency, and
a more bandwidth-sensitive application may focus on available
bandwidth.
In this document, we define eleven Cost Metrics, extending the base
ALTO protocol [ALTO], which has defined only a single Cost Metric,
i.e., the generic "routingcost" metric (Sec. 14.2 of ALTO base
specification [ALTO]).
The Cost Metrics that we define in this document focus on traffic
engineering. Additional metrics may be defined in other documents.
In particular, the Cost Metrics that we define in this document can
be gathered from routing systems; [RFC3630], [RFC3784], [OSPF-TE],
[ISIS-TE], [BGP-LS] and [BGP-PM] define mechanisms that allow an ALTO
Server to retrieve and derive the necessary information to provide
the metrics that we define in this document.
Note that the metrics that the ALTO Server retrieves may be defined
for only links, and hence, the server will need to compose the link
metrics to obtain path metrics used in services such as the Cost Map
Service. In this definition, we define the metrics to be independent
of link or path, considering that future ALTO extensions may define
link-based services, and hence the defined metrics should still be
usable.
One challenge in defining the metrics is that performance metrics
often depend on configuration parameters. For example, the value of
packet loss rate depends on the measurement interval and varies over
time. To handle this issue, ALTO server may collect data on time
periods covering the past, present or only collect data on present
time.
The definitions of a set of Cost Metrics can allow us to extend the
base protocol (e.g., allowing output and constraints use different
Cost Metrics), but such extensions are not in the scope of this
document.
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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].
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3. Metric: Delay
Cost Metric name:
Delay
Metric Description:
To specify spatial and temporal aggregated delay between the
specified source and destination. The spatial aggregation unit is
specified in the query context (e.g., PID to PID, or endhost to
endhost); and the temporal unit is specified as the measurement
interval in the query context. The delay is the time that the
packet spends to travel from source to destination.
Metric Unit:
The unit is microsecond.
Metric Value Type:
A single 'JSONNumber' type value containing a non-negative integer
component that may be followed by an exponent part.
Cost Mode:
A Cost Mode is encoded as a US-ASCII string. The string MUST
either have the value 'numerical' or 'ordinal'.
Collection Method:
The delay metric is part of ALTO information provided by ALTO
server. ALTO server may collect delay metric from routing
protocol or deploy data source to collect data to compute the
delay metrics [ALTO-DEPLOYMENT]. The data source can be either
log server or OAM system or P2P client,etc.
When the delay metric is collected from routing protocol, it is
measured over a measurement interval preconfigured by routing
protocol. As described in Section 5 of [ISIS-TE],the default
measurement interval is set to 30 seconds.
ALTO server may also have additional data processing such as
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aggregating the results across multiple systems, remove outliers,
create additional statistics.
When the data is collected from data source or collected from
routing protocol, Either scheduling can be used so that the past
and present results for the delay metrics over a period of time
are recorded, e.g., measured every hours and aggregated, or only
the latest update is recorded.
ALTO Sample interval:
The ALTO Server may collect values from the sources measurements
done e.g. every second over a period of 30 seconds. The ALTO
Server may then aggregate these values over ALTO Sample intevals
of at least 30 seconds and provide updates every hour.
Use and Applications:
This is intended to be a constraint attribute value.It could be
used as a cost metric constraint attribute used either together
with cost metric attribute 'routingcost' or on its own or as a
returned cost metric in the response.
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Example 1: Delay value on source-destination endpoint pairs
POST /endpointcost/lookup HTTP/1.1
Host: alto.example.com
Content-Length: TBA
Content-Type: application/alto-endpointcostparams+json
Accept: application/alto-endpointcost+json,application/alto-error+json
{
"cost-type": {"cost-mode" : "numerical",
"cost-metric" : "delay"},
"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: TBA
Content-Type: application/alto-endpointcost+json
{
"meta" :{
"cost-type": {"cost-mode" : "numerical",
"cost-metric" : "delay"
}
},
"endpoint-cost-map" : {
"ipv4:192.0.2.2": {
"ipv4:192.0.2.89" : 10,
"ipv4:198.51.100.34" : 20,
"ipv4:203.0.113.45" : 30,
}
}
}
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4. Metric: Delayjitter
Cost Metric name:
Delayjitter
Metric Description:
To specify spatial and temporal aggregated jitter (latency
variation) over the specified source and destination. The spatial
aggregation unit is specified in the query context (e.g., PID to
PID, or endhost to endhost); and the temporal unit is specified as
the measurement interval in the query context.
Metric Unit:
The unit is microsecond.
Metric Value Type:
A single 'JSONumber' type value containing an integer component
that may be followed by exponent part.
Cost Mode:
A Cost Mode is encoded as a US-ASCII string. The string MUST
either have the value 'numerical' or 'ordinal'.
Collection Method:
The delayjitter metric is part of ALTO information provided by
ALTO server. ALTO server may collect delayjitter metric from
routing protocol or deploy data source to collect data to compute
the delay metrics [ALTO-DEPLOYMENT]. The data source can be
either log server or OAM system or P2P client, etc.
When the delayjitter metric is collected from routing protocol, it
is measured over a measurement interval preconfigured by routing
protocol. As described in Section 5 of [ISIS-TE], the default
measurement interval is set to 30 seconds.
ALTO server may also have additional data processing such as
aggregating the results across multiple systems, remove outliers,
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create additional statistics.
When the data is collected from data source or collected from
routing protocol, either scheduling can be used so that the past
and present results for the delayjitter metrics over a period of
time can be recorded, e.g., measured every hours,or only measure
the latest update.
ALTO Sample interval:
The ALTO Server may collect values from the sources measurements
done e.g. every second over a period of 30 seconds. The ALTO
Server may then aggregate these values over ALTO Sample intevals
of at least 30 seconds and provide updates every hour.
Use and Applications:
This is intended to be a constraint attribute value.It could be
used as a cost metric constraint attribute used either together
with cost metric attribute 'routingcost' or on its own or as a
returned cost metric in the response.
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Example 2: Delayjitter value on source-destination endpoint pairs
POST /endpointcost/lookup HTTP/1.1
Host: alto.example.com
Content-Length: TBA
Content-Type: application/alto-endpointcostparams+json
Accept: application/alto-endpointcost+json,application/alto-error+json
{
"cost-type": {"cost-mode" : "numerical",
"cost-metric" : "delayjitter"},
"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: TBA
Content-Type: application/alto-endpointcost+json
{
"meta": {
"cost type": {
"cost-mode": "numerical",
"cost-metric":"delayjitter"
}
},
"endpoint-cost-map": {
"ipv4:192.0.2.2": {
"ipv4:192.0.2.89" : 0
"ipv4:198.51.100.34" : 1
"ipv4:203.0.113.45" : 5
}
}
}
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5. Metric: Pktloss
Cost Metric name:
pktloss
Metric Description:
To specify spatial and temporal aggregated packet loss over the
specified source and destination. The spatial aggregation unit is
specified in the query context (e.g., PID to PID, or endhost to
endhost); and the temporal unit is specified as the measurement
interval in the query context.
Metric Unit:
The unit is percentile.
Metric Value Type:
A single number value containing an integer component that may be
followed by a fraction part and/or an exponent part.
Cost Mode:
A Cost Mode is encoded as a US-ASCII string. The string MUST
either have the value 'numerical' or 'ordinal'.
Collection Method:
The pktloss metric is part of ALTO information provided by ALTO
server. ALTO server may collect pktloss metric from routing
protocol or deploy data source to collect data to compute the
delay metrics [ALTO-DEPLOYMENT]. The data source can be either
log server or OAM system or P2P client,etc.
When the pktloss metric is collected from routing protocol, it is
measured over a measurement interval preconfigured by routing
protocol. As described in Section 5 of [ISIS-TE], the default
measurement interval is set to 30 seconds.
ALTO server may also have additional data processing such as
aggregating the results across multiple systems, remove outliers,
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create additional statistics.
When the data is collected from data source or collected from
routing protocol, either scheduling can be used so that the past
and present results for this metric over a period of time can be
recorded, e.g.,measured every hours,or only measure the latest
update.
ALTO Sample interval:
The ALTO Server may collect values from the sources measurements
done e.g. every second over a period of 30 seconds. The ALTO
Server may then aggregate these values over ALTO Sample intevals
of at least 30 seconds and provide updates every hour.
Use and Applications:
This is intended to be a constraint attribute value. It could be
used as a cost metric constraint attribute used either together
with cost metric attribute 'routingcost' or on its own or as a
returned cost metric in the response.
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Example 3: pktloss value on source-destination endpoint pairs
POST /endpointcost/lookup HTTP/1.1
Host: alto.example.com
Content-Length: TBA
Content-Type: application/alto-endpointcostparams+json
Accept: application/alto-endpointcost+json,application/alto-error+json
{
"cost-type": {"cost-mode" : "numerical",
"cost-metric" : "pktloss"},
"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: TBA
Content-Type: application/alto-endpointcost+json
{
"meta": {
"cost type": {
"cost-mode": "numerical",
"cost-metric":"pktloss"}
}
},
"endpoint-cost-map": {
"ipv4:192.0.2.2": {
"ipv4:192.0.2.89" : 0,
"ipv4:198.51.100.34": 1,
"ipv4:203.0.113.45" : 2,
}
}
}
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6. Metric: Hopcount
The metric hopcount is mentioned in [ALTO] as an example. This
section further clarifies its properties.
Cost Metric name:
Hopcount
Metric Description:
To specify the number of hops in the path between the source
endpoint and the destination endpoint.
Editor Note: Need to specify which level (AS, IP perhaps), details
TBD for multiple-layer aspect.
Metric Unit:
The unit is integer number.
Metric Value Type:
A single 'JSONNumber' type value containing an integer component.
Cost Mode:
A Cost Mode is encoded as a US-ASCII string. string MUST either
have the value 'numerical' or 'ordinal'.
ALTO Sample interval:
The ALTO Server may collect values from the sources measurements
done e.g. every second over a period of 30 seconds. The ALTO
Server may then aggregate these values over ALTO Sample intevals
of at least 30 seconds and provide updates every hour.
Use and Applications:
This is intended to be a constraint attribute value. It could be
used as a cost metric constraint attribute used either together
with cost metric attribute 'routingcost' or on its own or as a
returned cost metric in the response.
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7. Metric: Bandwidth
Cost Metric name:
Bandwidth
Metric Description:
To specify spatial and temporal aggregated bandwidth over the
specified source and destination. The spatial aggregation unit is
specified in the query context (e.g., PID to PID, or endhost to
endhost); and the temporal unit is specified as the measurement
interval in the query context.
Metric Unit:
The units are bytes per second.
Metric Value Type:
A single 'JSONNumber' type 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.
Cost Mode:
A Cost Mode is encoded as a US-ASCII string. string MUST either
have the value 'numerical' or 'ordinal'.
ALTO Sample interval:
The ALTO Server may collect values from the sources measurements
done e.g. every second over a period of 30 seconds. The ALTO
Server may then aggregate these values over ALTO Sample intevals
of at least 30 seconds and provide updates every hour.
Use and Applications:
This is just a definition of a class of cost metric 'bandwidth'.
The use of this cost metric is always in conjunction with what it
represents, which could be Max Bandwidth (maxbw), Residual
Bandwidth (residuebw) etc.
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This is intended to be a constraint attribute value It could be
used as a cost metric constraint attribute used together with cost
metric attribute 'routingcost' or on its own or as a returned cost
metric in the response.
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8. Metric: Maximum Bandwidth
Cost Metric name:
Maximum Bandwidth
Metric Description:
To specify spatial and temporal maximum bandwidth over the
specified source and destination. The spatial aggregation unit is
specified in the query context (e.g., PID to PID, or endhost to
endhost); and the temporal unit is specified as the measurement
interval in the context interval.
Metric Unit:
The units are bytes per second.
Metric Value Type:
A single 'JSONNumber' type value containing an integer component
that may be followed by an exponent part.
Cost Mode:
A Cost Mode is encoded as a US-ASCII string. The string MUST
either have the value 'numerical' or 'ordinal'.
Collection Method:
The Maximum Bandwidth metric is gathered using [RFC3630],
[RFC3784] or [BGP-LS]. It is extended from Bandwidth cost metric
and is part of ALTO information provided by ALTO server. ALTO
server may collect Maximum Bandwidth metric from routing protocol
or deploy data source to collect data to compute the delay metrics
[ALTO-DEPLOYMENT]. The data source can be either log server or
OAM system or P2P client,etc.
When the Maximum Bandwidth metric is collected from routing
protocol, it is measured over a measurement interval preconfigured
by routing protocol. As described in Section 5 of [ISIS-TE], the
default measurement interval is set to 30 seconds.
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ALTO server may also have additional data processing such as
aggregating the results across multiple systems, remove outliers,
create additional statistics.
When the data is collected from data source or collected from
routing protocol, either scheduling can be used so that the past
and present results for this metric over a period of time can be
recorded, e.g.,measured every hours,or only measure the latest
update.
ALTO Sample interval:
The ALTO Server may collect values from the sources measurements
done e.g. every second over a period of 30 seconds. The ALTO
Server may then aggregate these values over ALTO Sample intevals
of at least 30 seconds and provide updates every hour.
Use and Applications:
This is intended to be a constraint attribute value. It could be
used as a cost metric constraint attribute used either together
with cost metric attribute 'routingcost' or on its own or as a
returned cost metric in the response.
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Example 4: maxbw value on source-destination endpoint pairs
POST/ endpointcost/lookup HTTP/1.1
Host: alto.example.com
Content-Length: TBA
Content-Type: application/alto-endpointcostparams+json
Accept: application/alto-endpointcost+json,application/alto-error+json
{
"cost-type": { "cost-mode": "numerical",
"cost-metric": "maxbw"},
"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: TBA
Content-Type: application/alto-endpointcost+json
{
"meta": {
"cost-type": {
"cost-mode": "numerical",
"cost-metric": "maxbw"
}
},
"endpoint-cost-map": {
"ipv4:192.0.2.2": {
"ipv4:192.0.2.89": 0,
"ipv4:198.51.100.34" : 2000,
"ipv4:203.0.113.45": 5000,
}
}
}
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9. Metric: Maximum Reserved Bandwdith
Cost Metric name:
Maximum Reserved Bandwidth
Metric Description:
To specify spatial and temporal maximum reserved bandwidth over
the specified source and destination. The spatial aggregation
unit is specified in the query context (e.g., PID to PID, or
endhost to endhost); and the temporal unit is specified as the
measurement interval in the query context.
Metric Unit:
The units are bytes per second.
Metric Value Type:
A single 'JSONNumber' type value containing an integer component
that may be followed by an exponent part.
Cost Mode:
A Cost Mode is encoded as a US-ASCII string. The string MUST
either have the value 'numerical' or 'ordinal'.
Collection Method:
The Maximum Reserved Bandwdith is gathered using [RFC3630],
[RFC3784] or [BGP-LS]. It is extended from Bandwidth Cost metric
defined as part of ALTO information provided by ALTO server. ALTO
server may collect Maximum Reserved Bandwdith metric from routing
protocol or deploy data source to collect data to compute the
delay metrics [ALTO-DEPLOYMENT]. The data source can be either
log server or OAM system or P2P client,etc.
When the Maximum Reserved Bandwdith metric is collected from
routing protocol, it is measured over a measurement interval
preconfigured by routing protocol. As described in Section 5 of
[ISIS-TE], the default measurement interval is set to 30 seconds.
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ALTO server may also have additional data processing such as
aggregating the results across multiple systems, remove outliers,
create additional statistics.
When the data is collected from data source or collected from
routing protocol, either scheduling can be used so that the past
and present results for this metric over a period of time can be
recorded, e.g.,measured every hours,or only measure the latest
update.
ALTO Sample interval:
The ALTO Server may collect values from the sources measurements
done e.g. every second over a period of 30 seconds. The ALTO
Server may then aggregate these values over ALTO Sample intevals
of at least 30 seconds and provide updates every hour.
Use and Applications:
This is intended to be a constraint attribute value. It could be
used as a cost metric constraint attribute used either together
with cost metric attribute 'routingcost' or on its own or as a
returned cost metric in the response.
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Example 5: maxresbw value on source-destination endpoint pairs
POST/ endpointcost/lookup HTTP/1.1
Host: alto.example.com
Content-Length: TBA
Content-Type: application/alto-endpointcostparams+json
Accept: application/alto-endpointcost+json,application/alto-error+json
{
"cost-type" { "cost-mode": "numerical",
"cost-metric": "maxresbw"},
"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: TBA
Content-Type: application/alto-endpointcost+json
{
"meta": {
"cost-type": {
"cost-mode": "numerical",
"cost-metric": "maxresbw"
}
},
" endpoint-cost-map": {
"ipv4:192.0.2.2" {
"ipv4:192.0.2.89" : 0,
"ipv4:198.51.100.34": 2000,
"ipv4:203.0.113.45": 5000,
}
}
}
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10. Metric: Unavailable Reserved Bandwidth
Cost Metric name:
Unavailable Reserved Bandwidth
Metric Description:
To specify spatial and temporal unavailable reserved bandwidth
over the specified source and destination. The spatial
aggregation unit is specified in the query context (e.g., PID to
PID, or endhost to endhost); and the temporal unit is specified as
the measurement interval in the query context.
Metric Unit:
The units are bytes per second.
Metric Value Type:
A single 'JSONArray' type with each value containing an integer
component that may be followed by an exponent part.
Cost Mode:
A Cost Mode is encoded as a US-ASCII string. The string MUST
either have the value 'numerical' or 'ordinal'.
Collection Method:
The Unavailable Reserved Bandwidth metric is gathered using
[RFC3630], [RFC3784] or [BGP-LS]. It is extended from Bandwidth
Cost metric and defined as part of ALTO information provided by
ALTO server. ALTO server may collect Unavailable Reserved
Bandwidth metric from routing protocol or deploy data source to
collect data to compute the delay metrics [ALTO-DEPLOYMENT]. The
data source can be either log server or OAM system or P2P
client,etc.
When the Unavailable Reserved Bandwidth metric is collected from
routing protocol, it is measured over a measurement interval
preconfigured by routing protocol. As described in Section 5 of
[ISIS-TE],the default measurement interval is set to 30 seconds.
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ALTO server may also have additional data processing such as
aggregating the results across multiple systems, remove outliers,
create additional statistics.
When the data is collected from data source or collected from
routing protocol, either scheduling can be used so that the past
and present results for this metric over a period of time can be
recorded, e.g.,measured every hours,or only measure the latest
update.
ALTO Sample interval:
The ALTO Server may collect values from the sources measurements
done e.g. every second over a period of 30 seconds. The ALTO
Server may then aggregate these values over ALTO Sample intevals
of at least 30 seconds and provide updates every hour.
Use and Applications:
This is intended to be a constraint attribute values. The values
correspond to the bandwidth that can be reserved with a setup
priority of 0 through 7. It could be used as a cost metric
constraint attribute used Either together with cost metric
attribute 'routingcost' or on its own or as a returned cost metric
in the response.
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Example 6: unresbw value on source-destination endpoint pairs
In this example, the Collection method specifies that the
'unresbw' values are defined as the 'unavailable bandwidth' specified
in section 2.5.8 of RFC3630: 8 unavailable bandwidth value are
reported in the same OSPF message using the same TLV. Each value
is corresponding to the bandwidth that can be reserved with a setup
priority of 0 through 7.
POST/ endpointcost/lookup HTTP/1.1
Host: alto.example.com
Content-Length: TBA
Content-Type: application/alto-endpointcostparams+json
Accept: application/alto-endpointcost+json,application/alto-error+json
{
"cost-type" { "cost-mode": "numerical",
"cost-metric": "unresbw[1,8]" },
"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: TBA
Content-Type: application/alto-endpointcost+json
{
"meta": {
"cost-type": {
"cost-mode": "numerical",
"cost-metric": "unresbw[1,8]"
}
},
"endpoint-cost-map" {
"ipv4:192.0.2.2" {
"ipv4:192.0.2.89" : [0,0,0,0,0,0,0,0],
"ipv4:198.51.100.34": [0,0,0,0,0,0,0,2000],
"ipv4:203.0.113.45": [0,0,0,0,0,0,0,5000],
}
}
}
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11. Metric: Residue Bandwidth
Cost Metric name:
Residue Bandwidth
Metric Description:
To specify spatial and temporal residual bandwidth over the
specified source and destination. The spatial aggregation unit is
specified in the query context (e.g., PID to PID, or endhost to
endhost); and the temporal unit is specified as the measurement
interval in the query context.
Metric Unit:
The units are bytes per second.
Metric Value Type:
A single 'JSONArray' type with each value containing an integer
component that may be followed by an exponent part.
Cost Mode:
A Cost Mode is encoded as a US-ASCII string. The string MUST
either have the value 'numerical' or 'ordinal'.
Collection Method:
The Residue Bandwidth metric is gathered using [OSPF-TE],
[ISIS-TE] or [BGP-PM]. It is extended from Bandwidth Cost metric
and is part of ALTO information provided by ALTO server. ALTO
server may collect Residue Bandwidth metric from routing protocol
or deploy data source to collect data to compute the delay metrics
[ALTO-DEPLOYMENT]. The data source can be either log server or
OAM system or P2P client,etc.
When the Residue Bandwidth metric is collected from routing
protocol, it is measured over a measurement interval preconfigured
by routing protocol. As described in Section 5 of [ISIS-TE],the
default measurement interval is set to 30 seconds.
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ALTO server may also have additional data processing such as
aggregating the results across multiple systems, remove outliers,
create additional statistics.
When the data is collected from data source or collected from
routing protocol, either scheduling can be used so that the past
and present results for this metric over a period of time can be
recorded, e.g.,measured every hours,or only measure the latest
update.
ALTO Sample interval:
The ALTO Server may collect values from the sources measurements
done e.g. every second over a period of 30 seconds. The ALTO
Server may then aggregate these values over ALTO Sample intevals
of at least 30 seconds and provide updates every hour.
Use and Applications:
This is intended to be a constraint attribute values. The values
correspond to the bandwidth that can be reserved with a setup
priority of 0 through 7. It could be used as a cost metric
constraint attribute used Either together with cost metric
attribute 'routingcost' or on its own or as a returned cost metric
in the response.
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Example 7: residuebw value on source-destination endpoint pairs
POST/ endpointcost/lookup HTTP/1.1
Host: alto.example.com
Content-Length: TBA
Content-Type: application/alto-endpointcostparams+json
Accept: application/alto-endpointcost+json,application/alto-error+json
{
"cost-type": { "cost-mode": "numerical",
"cost-metric": "residubw"},
"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: TBA
Content-Type: application/alto-endpointcost+json
{
"meta": {
"cost-type" {
"cost-mode": "numerical",
"cost-metric": "residubw"
}
},
"endpoint-cost-map" {
"ipv4:192.0.2.2" {
"ipv4:192.0.2.89" : 0,
"ipv4:198.51.100.34": 2000,
"ipv4:203.0.113.45": 5000,
}
}
}
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12. Metric: Available Bandwidth
Cost Metric name:
Available Bandwidth
Metric Description:
To specify spatial and temporal availaible bandwidth over the
specified source and destination. The spatial aggregation unit is
specified in the query context (e.g., PID to PID, or endhost to
endhost); and the temporal unit is specified as the measurement
interval in the query context.
Metric Unit:
The units are bytes per second.
Metric Value Type:
A single 'JSONArray' type with each value containing an integer
component that may be followed by an exponent part.
Cost Mode:
A Cost Mode is encoded as a US-ASCII string. The string MUST
either have the value 'numerical' or 'ordinal'.
Collection Method:
The Available Bandwidth metric is gathered using [OSPF-TE],
[ISIS-TE] or [BGP- PM]. It is extended from Bandwidth Cost metric
and is part of ALTO information provided by ALTO server. ALTO
server may collect Available Bandwidth metric from routing
protocol or deploy data source to collect data to compute the
delay metrics [ALTO-DEPLOYMENT]. The data source can be either
log server or OAM system or P2P client,etc.
When the Available Bandwidth metric is collected from routing
protocol, it is measured over a measurement interval preconfigured
by routing protocol. As described in Section 5 of [ISIS-TE],the
default measurement interval is set to 30 seconds.
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ALTO server may also have additional data processing such as
aggregating the results across multiple systems, remove outliers,
create additional statistics.
When the data is collected from data source or collected from
routing protocol, either scheduling can be used so that the past
and present results for this metric over a period of time can be
recorded, e.g.,measured every hours,or only measure the latest
update.
ALTO Sample interval:
The ALTO Server may collect values from the sources measurements
done e.g. every second over a period of 30 seconds. The ALTO
Server may then aggregate these values over ALTO Sample intevals
of at least 30 seconds and provide updates every hour.
Use and Applications:
This is intended to be a constraint attribute values. The values
correspond to the bandwidth that can be reserved with a setup
priority of 0 through 7. It could be used as a cost metric
constraint attribute used Either together with cost metric
attribute 'routingcost' or on its own or as a returned cost metric
in the response.
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Example 8: availbw value on source-destination endpoint pairs
POST /endpointcost/lookup HTTP/1.1
Host: alto.example.com
Content-Length: TBA
Content-Type: application/alto-endpointcostparams+json
Accept: application/alto-endpointcost+json,application/alto-error+json
{
"cost-type": { "cost-mode": "numerical",
"cost-metric": "availbw"},
"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: TBA
Content-Type: application/alto-endpointcost+json
{
"meta": {
"cost-type": {
"cost-mode": "numerical",
"cost-metric": "availbw"
}
},
"endpoint-cost-map": {
"ipv4:192.0.2.2" {
"ipv4:192.0.2.89" : 0,
"ipv4:198.51.100.34": 2000,
"ipv4:203.0.113.45": 5000,
}
}
}
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13. Metric: Utilized Bandwidth
Cost Metric name:
Utilized Bandwidth
Metric Description:
To specify spatial and temporal utilized bandwidth over the
specified source and destination. The spatial aggregation unit is
specified in the query context (e.g., PID to PID, or endhost to
endhost); and the temporal unit is specified as the measurement
interval in the query context.
Metric Unit:
The units are bytes per second.
Metric Value Type:
A single 'JSONArray' type with each value containing an integer
component that may be followed by an exponent part.
Cost Mode:
A Cost Mode is encoded as a US-ASCII string. The string MUST
either have the value 'numerical' or 'ordinal'.
Collection Method:
The Utilized Bandwidth metric is gathered using [OSPF-TE],
[ISIS-TE] or [BGP-PM]. It is extended from bandwidth cost metric
and is part of ALTO information provided by ALTO server. ALTO
server may collect Utilized Bandwidth metric from routing protocol
or deploy data source to collect data to compute the delay metrics
[ALTO-DEPLOYMENT]. The data source can be either log server or
OAM system or P2P client,etc.
When The Utilized Bandwidth metric is collected from routing
protocol, it is measured over a measurement interval preconfigured
by routing protocol. As described in Section 5 of [ISIS-TE],the
default measurement interval is set to 30 seconds.
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ALTO server may also have additional data processing such as
aggregating the results across multiple systems, remove outliers,
create additional statistics.
When the data is collected from data source or collected from
routing protocol, either scheduling can be used so that the past
and present results for this metric over a period of time can be
recorded, e.g.,measured every hours,or only measure the latest
update.
ALTO Sample interval:
The ALTO Server may collect values from the sources measurements
done e.g. every second over a period of 30 seconds. The ALTO
Server may then aggregate these values over ALTO Sample intevals
of at least 30 seconds and provide updates every hour.
Use and Applications:
This is intended to be a constraint attribute values. The values
correspond to the bandwidth that can be reserved with a setup
priority of 0 through 7. It could be used as a cost metric
constraint attribute used Either together with cost metric
attribute 'routingcost' or on its own or as a returned cost metric
in the response.
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Example 9: utilbw value on source-destination endpoint pairs
POST /endpointcost/lookup HTTP/1.1
Host: alto.example.com
Content-Length: TBA
Content-Type: application/alto-endpointcostparams+json
Accept: application/alto-endpointcost+json,application/alto-error+json
{
"cost-type": {"cost-mode" : "numerical",
"cost-metric" : "utilbw"},
"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: TBA
Content-Type: application/alto-endpointcost+json
{
"meta": {
"cost type": {
"cost-mode": "numerical",
"cost-metric": "utilbw"
}
},
"endpoint-cost-map": {
"ipv4:192.0.2.2" {
"ipv4:192.0.2.89" : 0,
"ipv4:198.51.100.34" : 2000,
"ipv4:203.0.113.45" : 5000,
}
}
}
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14. Security Considerations
The properties defined in this document present no security
considerations beyond those in Section 15 of the base ALTO
specification [ALTO].
However concerns addressed in Sections "15.1 Authenticity and
Integrity of ALTO Information", "15.2 Potential Undesirable Guidance
from Authenticated ALTO Information" and "15.3 Confidentiality of
ALTO Information" remain of utmost importance. Indeed, TE
performance is a highly sensitive ISP information and sharing TE
metric values in numerical mode requires full mutual confidence
between the entities managing the ALTO Server and Client. Numerical
TE performance information will most likely be distributed by ALTO
Servers to Clients under strict and formal mutual trust agreements.
One the other hand, ALTO Clients must be cognizant on the risks
attached to such information that they would have acquired outside
formal conditions of mutual trust.
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15. IANA Considerations
IANA has added the following entries to the ALTO cost map Properties
registry, defined in Section 3 of [RFCXXX].
+-----------+--------------+------------------------+
| Namespace | Property | Reference |
+-----------+--------------+------------------------+
| | delay | [RFCxxxx], Section 3 |
| | jitter | [RFCxxxx], Section 4 |
| | pktloss | [RFCxxxx], Section 5 |
| | hopcount | [RFCxxxx], Section 6 |
| | bandwidth | [RFCxxxx], Section 7 |
| | maxbw |[RFCxxxx], Section 8 |
| | maxresbw |[RFCxxxx], Section 9 |
| | unresdbw |[RFCxxxx], Section 10 |
| | residbw |[RFCxxxx], Section 11 |
| | availbw |[RFCxxxx], Section 12 |
| | utilbw |[RFCxxxx], Section 13 |
+-----------+--------------+------------------------+
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16. References
16.1. Normative References
[ALTO] Alimi, R., "ALTO Protocol",
ID draft-ietf-alto-protocol-16, May 2013.
[BGP-LS] Gredler, H., "North-Bound Distribution of Link-State and
TE Information using BGP",
ID draft-ietf-idr-ls-distribution-03, May 2013.
[BGP-PM] Wu, Q., "BGP attribute for North-Bound Distribution of
Traffic Engineering (TE) performance Metrics",
ID draft-wu-idr-te-pm-bgp-02, October 2013.
[ISIS-TE] Giacalone, S., "ISIS Traffic Engineering (TE) Metric
Extensions", ID draft-ietf-isis-te-metric-extensions-01,
October 2013.
[OSPF-TE] 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.
16.2. Informative References
[ALTO-DEPLOYMENT]
Stiemerling, M., Kiesel, S., Previdi, S., and M. Scharf,
"ALTO Deployment Considerations",
ID draft-ietf-alto-deployments-08, October 2013.
[RFC6390] Clark, A. and B. Claise, "Framework for Performance Metric
Development", RFC 6390, July 2011.
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Authors' Addresses
Qin Wu
Huawei
101 Software Avenue, Yuhua District
Nanjing, Jiangsu 210012
China
Email: sunseawq@huawei.com
Y. Richard Yang
Yale University
51 Prospect St
New Haven, CT 06520
USA
Email: yry@cs.yale.edu
Young Lee
Huawei
1700 Alma Drive, Suite 500
Plano, TX 75075
USA
Email: leeyoung@huawei.com
Dhruv Dhody
Huawei
Leela Palace
Bangalore, Karnataka 560008
INDIA
Email: dhruv.ietf@gmail.com
Sabine Randriamasy
Alcatel-Lucent
Route de Villejust
Nozay, 91460
FRANCE
Email: Sabine.Randriamasy@alcatel-lucent.com
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