ALTO Extension: Flow-based Cost Query
draft-gao-alto-fcs-05
The information below is for an old version of the document.
| Document | Type |
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|---|---|---|---|
| Authors | Jingxuan Zhang , Kai Gao , Junzhuo Austin Wang , Qiao Xiang , Y. Richard Yang | ||
| Last updated | 2018-03-04 | ||
| RFC stream | (None) | ||
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| Additional resources | |||
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draft-gao-alto-fcs-05
ALTO WG J. Zhang
Internet-Draft Tongji University
Intended status: Standards Track K. Gao
Expires: September 6, 2018 Tsinghua University
J. Wang
Tongji University
Q. Xiang
Tongji/Yale University
Y. Yang
Yale University
March 5, 2018
ALTO Extension: Flow-based Cost Query
draft-gao-alto-fcs-05.txt
Abstract
ALTO cost maps and endpoint cost services map a source-destination
pair into a cost value. However, current filter specifications,
which define the set of source-destination pairs in an ALTO query,
have two limitations: 1) Only very limited address types are
supported (IPv4 and IPv6), which is not sufficient to uniquely
identify a flow in networks with fine-grained routing, such as the
emerging Software Defined Networks. 2) The base ALTO protocol only
defines filters enumerating all sources and all destinations, leading
to redundant information in the response. To address these two
issues, this document extends the base ALTO protocol with a more
fine-grained filter type which allows ALTO clients to select only the
concerned source-destination pairs, and a more expressive address
space which allows ALTO clients to make queries beyond the limited IP
addresses.
Requirements Language
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].
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/.
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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 September 6, 2018.
Copyright Notice
Copyright (c) 2018 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
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the Trust Legal Provisions and are provided without warranty as
described in the Simplified BSD License.
Table of Contents
1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 3
2. Terminology . . . . . . . . . . . . . . . . . . . . . . . . . 4
2.1. Flow . . . . . . . . . . . . . . . . . . . . . . . . . . 4
3. Overview of Approaches . . . . . . . . . . . . . . . . . . . 4
3.1. Extended Endpoint Address . . . . . . . . . . . . . . . . 5
3.2. Flow-based Filter . . . . . . . . . . . . . . . . . . . . 5
4. Changes Since Version -01 . . . . . . . . . . . . . . . . . . 5
5. Extended Endpoint Address . . . . . . . . . . . . . . . . . . 6
5.1. Address Type . . . . . . . . . . . . . . . . . . . . . . 7
5.2. Endpoint Address . . . . . . . . . . . . . . . . . . . . 7
5.2.1. MAC Address . . . . . . . . . . . . . . . . . . . . . 7
5.2.2. Domain Name . . . . . . . . . . . . . . . . . . . . . 8
5.2.3. IPv4 Socket Address . . . . . . . . . . . . . . . . . 8
5.2.4. IPv6 Socket Address . . . . . . . . . . . . . . . . . 8
5.3. Address Type Compatibility . . . . . . . . . . . . . . . 8
5.4. Examples . . . . . . . . . . . . . . . . . . . . . . . . 9
6. Extended Cost Query Filters . . . . . . . . . . . . . . . . . 9
6.1. Filtered Cost Map Extension . . . . . . . . . . . . . . . 9
6.1.1. Capabilities . . . . . . . . . . . . . . . . . . . . 9
6.1.2. Accept Input Parameters . . . . . . . . . . . . . . . 10
6.2. Endpoint Cost Service Extension . . . . . . . . . . . . . 10
6.2.1. Capabilities . . . . . . . . . . . . . . . . . . . . 11
6.2.2. Accept Input Parameters . . . . . . . . . . . . . . . 11
6.3. Examples . . . . . . . . . . . . . . . . . . . . . . . . 12
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6.3.1. Information Resource Directory . . . . . . . . . . . 12
6.3.2. Flow-based Filtered Cost Map Service . . . . . . . . 13
6.3.3. Flow-based Endpoint Cost Service Example . . . . . . 14
7. Security Considerations . . . . . . . . . . . . . . . . . . . 15
8. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 16
8.1. ALTO Address Type Registry . . . . . . . . . . . . . . . 16
8.2. ALTO Address Type Compatibility Registry . . . . . . . . 16
9. Acknowledgment . . . . . . . . . . . . . . . . . . . . . . . 17
10. References . . . . . . . . . . . . . . . . . . . . . . . . . 17
10.1. Normative References . . . . . . . . . . . . . . . . . . 17
10.2. Informative References . . . . . . . . . . . . . . . . . 18
Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 19
1. Introduction
ALTO cost query services (Filtered Cost Map and Endpoint Cost
Service) can be regarded as functions transforming a given subset of
a specific query space into a network view abstract. However, the
current specification has some limitations.
First, in the base ALTO protocol [RFC7285], the endpoint cost filter
only contains the source and destination IP addresses. In practice,
both Internet Service Providers (ISP) and local network
administrators MAY conduct policy-based routing, e.g., P2P traffic
may be constrained and has a smaller bandwidth than HTTP traffic.
Also, web services with different QoS requirements may be hosted on
the same machine and have the same IP address but different paths
with different QoS metrics.
Second, in the base ALTO protocol [RFC7285], the query space is
defined by the lists of sources and destinations. For a query with N
sources and M destinations, the response contains NM entries. While
such a query schema is well suited for peer-to-peer (P2P)
applications where files of the same seed are stored on all hosts, it
may lead to a lot of redundancy in use cases such as modern data
analytics systems where replicas of the same dataset are stored on
only a small subset of servers. Consider a system where the number
of replicas is 3 (the default in HDFS), jointly scheduling N
concurrent transfers only needs a maximum of 3N entries but the base
ALTO protocol MAY return up to N^2 entries.
Thus, we can conclude that the following additional requirements (AR)
MUST be satisfied to allow ALTO clients make more accurate and
efficient cost queries.
AR-1: ALTO clients SHOULD be able to specify accurate query space in
cost query services.
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The base ALTO protocol only includes IPv4 and IPv6 addresses as
endpoint address types, which may not be sufficient to accurately
identify an endpoint with emerging flow-based routing mechanisms.
ALTO clients MAY suffer from suboptimal decisions because of such
inaccuracy. Thus, the ALTO protocol SHOULD be extended so that
clients CAN be able to specify accurate query space, i.e., with
more fine-grained endpoint address types.
AR-2: ALTO clients SHOULD be able to specify only the essential
query space in cost query services.
Existing PIDFilter (see Sec 11.3.2.3 in [RFC7285]) and
EndpointFilter (see Sec 11.5.1.3 in [RFC7285]) represent the
cross-product of sources and destinations, and can introduce a lot
of redundancy in certain use cases. This limitation CAN greatly
harm the scalability of the ALTO protocol. Thus, the ALTO
protocol SHOULD be extended so that ALTO clients CAN specify only
the essential cost query space, i.e., the concerned source-
destination pairs.
In this document, we describe an ALTO extension specifying flow-based
cost queries. The rest of this document is organized as follows.
Section 5 introduces several new address types that extend the query
space of ALTO cost services. Section 6 describes the extended schema
on Filtered Cost Map (FCM) and Endpoint Cost Service (ECS) to support
cost queries of arbitrary source-destination combinations. Section 7
and Section 8 discuss security and IANA considerations.
2. Terminology
This document uses the same terms as defined in [RFC7285] and
[RFC8189] with the following additional term:
2.1. Flow
In this document, a flow refers to all communications between two
endpoints. A flow is valid if and only if there CAN be valid
communications between the two endpoints, which oftentimes requires
that that two endpoint addresses have compatible address types.
3. Overview of Approaches
This section presents a non-normative overview of the extension to
support flow-based cost query. It assumes the readers are familiar
with Filtered Cost Map and Endpoint Cost Service defined in [RFC7285]
and their extensions defined in [RFC8189].
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3.1. Extended Endpoint Address
To allow ALTO clients specify accurate query space in cost query
services (AR-1), this document defines several new endpoint address
types. An endpoint address with a new type is referred to as an
extended endpoint address.
Since the address types of both the source and the destination
correspond to the same network flow, they MUST NOT conflict. This
document defines an address type conflict table to indicate
conflicts. If some source and destination address types in a query
conflict with each others, ALTO servers SHOULD return the
corresponding error.
3.2. Flow-based Filter
To allow ALTO clients specify only the essential query space in cost
query services (AR-2), both PIDFilter and EndpointFilter in the base
protocol MUST be extended. The extended filters are referred to as
flow-based filters.
A straight-forward way of satisfying AR-1 is to have an ALTO client
list all its concerned flows. Despite its simplicity, it MAY be too
large in size, especially when many flows have common sources or
common destinations in the query. Also from the implementation's
perspective, it cannot reuse the functionality to parse a PIDFilter/
EndpointFilter.
Thus, the flow-based filters defined in this document allow ALTO
clients to include multiple PIDFilter/EndpointFilter objects in the
same query. Apparently, if we replace each PIDFilter/EndpointFilter
of N sources and M destinations with NM filters that have exactly one
source and destination, the two representations refer to the same set
of flows. As a result, one can aggregate flows with common sources
or destinations in one PIDFilter/EndpointFilter object without
introducing redundant flows.
From the implementation's perspective, one MAY reuse an ALTO library
which parses PIDFilter/EndpointFilter and/or converts them into a set
of source-destination pairs.
4. Changes Since Version -01
Note to Editor: Please remove this section prior to publication.
This section records the change logs of the draft updates.
Changes since -04 revision:
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o Improve the clarity of the document by explicitly stating the
problems.
o Keep only flow in the terminology section.
o Move section 6 Advanced Flow-based Query out of this document.
o Change ALTO Address Type Conflicts Registry to ALTO Address Type
Compatibility Registry.
Changes since older versions:
Since -03 revision:
o Remove some irrelevant content from the draft.
o Improve the description of the new endpoint address type
identifier registry. And add a new registry to declare the
conflicting address type identifiers.
Since -02 revision:
o Change "EndpointURI" to "AddressType::EndpointAddr" for
consistency.
o Replace Cost Confidence by Cost Statistics for compatibility.
Since -01 revision:
o Define the basic flow-based query extensions for Filtered Cost Map
and Endpoint Cost service. The basic flow-based query is downward
compatible with the legacy ALTO service. It does not introduce
any new media types.
o Move the service of media-type application/alto-flowcost+json to
the advanced flow-based query extension. It will ask ALTO server
to support the new media type.
Since -00 revision:
o Change the schema of pid-flows and endpoint-flows fields from pair
list to pair mesh list.
5. Extended Endpoint Address
This document registers new address types and defines the
corresponding formats for endpoint addresses of each new address
type.
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5.1. Address Type
The new AddressType identifiers defined in this document are as
follows:
eth: An endpoint address with type eth is the address of an Ethernet
interface. It is used to uniquely identify an endpoint in the
data link layer.
domain: An endpoint address with type domain is the domain name of a
web service. It is used to uniquely identify a web service which
MAY be translated to one or more IPv4 address(es).
domain6: An endpoint address with type domain6 is the domain name of
a web service. It is used to uniquely identify a web service
which MAY be translated to one or more IPv6 address(es).
tcp: An endpoint address with type tcp is the address of a TCP
socket. It is used to uniquely identify an IPv4 TCP socket in the
transport layer.
tcp6: An endpoint address with type tcp6 is the address of a TCP
socket. It is used to uniquely identify an IPv6 TCP socket in the
transport layer.
udp: An endpoint address with type udp is the address of a UDP
socket. It is used to uniquely identify an IPv4 UDP socket in the
transport layer.
udp6: An endpoint address with type udp6 is the address of a UDP
socket. It is used to uniquely identify an IPv6 UDP socket in the
transport layer.
5.2. Endpoint Address
This document defines EndpointAddr when AddressType is in
Section 8.1.
5.2.1. MAC Address
An Endpoint Address of type eth is encoded as a MAC address, whose
format is encoded as specified by either format EUI-48 in [EUI48] or
EUI-64 in [EUI64].
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5.2.2. Domain Name
An Endpoint Address of type domain or domain6 is encoded as a domain
name, as specified in Section 11 of [RFC2181]. It MUST have at least
one corresponding A (domain) or AAAA (domain6) record in the DNS.
5.2.3. IPv4 Socket Address
An Endpoint Address of type tcp or udp is encoded as an IPv4 socket
address. It is encoded as a string of the format Host:Port with the
: character as a separator. The Host component of an IPv4 socket
address is encoded as specified by either an IPv4 address (see
Section 10.4.3.1 of [RFC7285]) or an IPv4-compatible domain name (see
Section 5.2.2). The Port component of an IPv4 socket address is
encoded as an integer between 1 and 65535.
5.2.4. IPv6 Socket Address
An Endpoint Address of type tcp6 or udp6 is encoded as an IPv6 socket
address. It is also encoded as a string of the format Host:Port with
the : character as a separator. The Host component of an IPv6 socket
address is encoded as specified by either an IPv6 address (see
Section 10.4.3.2 of [RFC7285]) enclosed in the [" and "] characters
or an IPv6-compatible domain name (see Section 5.2.2). The Port
component of IPv6 socket address is encoded as an integer between 1
and 65535.
5.3. Address Type Compatibility
In practice, a flow with endpoint addresses with different types MAY
NOT be valid. For example, a source endpoint with an IPv4 address
CANNOT establish a network connection with a destination endpoint
with an IPv6 address. Neither can a source with a TCP socket address
and a destination with a UDP socket address.
Thus, to explicitly define the compatibility between AddressType
identifiers, every ALTO AddressType identifier MUST provide a list of
AddressType identifiers that are compatible with it in the ALTO
Address Type Compatibility Registry Section 8.2. For all sources and
destinations in a PIDFilter/EndpointFilter, if the AddressType
identifiers of a given pair DO NOT appear in the ALTO Address Type
Compatibility Registry, an ALTO server MUST return an ALTO error
response with the error code "E_INVALID_FIELD_VALUE" with optional
information to help diagnose the incompatibility.
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5.4. Examples
Some valid endpoint addresses are demonstrated as follows:
"eth:98-e0-d9-9c-df-81"
"domain:www.example.com"
"tcp:198.51.100.34:5123"
"udp6:[2000::1:2345:6789:abcd]:8080"
6. Extended Cost Query Filters
This section describes extensions to [RFC7285] and [RFC8189] to
support flow-based cost queries.
This document uses the notation rules specified in Section 8.2 of
[RFC7285] and also the notation rule for optional fields in Section 4
of [RFC8189].
6.1. Filtered Cost Map Extension
This document extends the Filtered Cost Map as defined in
Section 11.3.2 of [RFC7285] and Section 4.1 of [RFC8189], by adding a
new capability and input parameters.
The media type, HTTP method, and uses specifications (described in
Sections 11.3.2.1, 11.3.2.2, and 11.3.2.5 of [RFC7285], respectively)
are unchanged.
The response is the same as defined in Section 4.1.3 of [RFC8189].
6.1.1. Capabilities
The Filtered Cost Map capabilities are extended with a new member:
o flow-based-filter
The capability flow-based-filter indicates whether this resource
supports flow-based cost queries. The FilteredCostMapCapabilities
object in Section 4.1.1 of [RFC8189] is extended as follows:
object {
JSONString cost-type-names<1..*>;
[JSONBool cost-constraints;]
[JSONNumber max-cost-types;]
[JSONString testable-cost-type-names<1..*>;]
[JSONBool flow-based-filter;]
} FilteredCostMapCapabilities;
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cost-type-names and cost-constraints: As defined in Section 11.3.2.4
of [RFC7285].
max-cost-types and testable-cost-type-names: As defined in
Section 4.1.1 of [RFC8189].
flow-based-filter: If true, an ALTO Server allows a field pid-flows
to be included in the requests. If not present, this field MUST
be interpreted as if it is false.
6.1.2. Accept Input Parameters
The ReqFilteredCostMap object in Section 4.1.2 of [RFC8189] is
extended as follows:
object {
[CostType cost-type;]
[CostType multi-cost-types<1..*>;]
[CostType testable-cost-types<1..*>;]
[JSONString constraints<0..*>;]
[JSONString or-constraints<1..*><1..*>;]
[PIDFilter pids;]
[PIDFilter pid-flows<1..*>;]
} ReqFilteredCostMap;
cost-type, multi-cost-types, testable-cost-types, constraints, or-
constraints: As defined in Section 4.1.2 of [RFC8189].
pids: As defined in Section 11.3.2.3 of [RFC7285].
pid-flows: Defined as a list of PIDFilter objects. The ALTO server
MUST interpret PID pairs appearing in multiple PIDFilter objects
as if they appeared only once.
An ALTO client MUST include either pids or pid-flows in a query but
MUST NOT include both at the same time.
6.2. Endpoint Cost Service Extension
This document extends the Endpoint Cost Service as defined in
Section 11.5.1 of [RFC7285] and Section 4.2 of [RFC8189], by adding a
new capability and input parameters.
The media type, HTTP method, and uses specifications (described in
Sections 11.5.1.1, 11.5.1.2, and 11.5.1.5 of [RFC7285], respectively)
are unchanged.
The response is the same as defined in Section 4.2.3 of [RFC8189].
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6.2.1. Capabilities
The extension to EndpointCostCapabilities includes two new members:
o address-types
o flow-based-filter
Only if the capability "flow-based-filter" is present and its value
is "true", the ALTO server supports the flow-based extension for this
endpoint cost service. The capability "address-types" indicates
which endpoint address types are supported by this resource, it MUST
NOT be included if "flow-based-filter" is absent or the value is
false.
object {
[JSONString address-types<0..*>;]
[JSONBool flow-based-filter;]
} EndpointCostCapabilities : FilteredCostMapCapabilities;
flow-based-filter: If true, an ALTO Server MUST accept field
"endpoint-flows" in the requests. If not present, this field MUST
be interpreted as if it is specified false.
address-types: Defines a list of AddressType identifiers encoded as
a JSONArray of JSONString. All AddressType identifiers MUST be
registered in the "ALTO Address Type Registry" (see Section 14.4
of [RFC7285]). An ALTO server SHOULD NOT claim "ipv4" and "ipv6"
in this field explicitly, because they are supported by default.
If not present, this field MUST be interpreted as if it is an
empty array, i.e., the ALTO server only supports the default
"ipv4" and "ipv6" address types.
6.2.2. Accept Input Parameters
The ReqEndpointCostMap object in Section 4.2.2 of [RFC8189] is
extended as follows:
object {
[CostType cost-type;]
[CostType multi-cost-types<1..*>;]
[CostType testable-cost-types<1..*>;]
[JSONString constraints<0..*>;]
[JSONString or-constraints<1..*><1..*>;]
[EndpointFilter endpoints;]
[EndpointFilter endpoint-flows<1..*>;]
} ReqEndpointCostMap;
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cost-type, multi-cost-types, testable-cost-types, constraints, or-
constraints:
As defined in Section 4.1.2 of [RFC8189].
endpoints: As defined in Section 11.5.1.3 of [RFC7285].
endpoint-flows: Defined as a list of EndpointFilter objects. The
ALTO server MUST interpret endpoint pairs appearing in multiple
EndpointFilter objects as if they appeared only once.
If the AddressType of the source and destination in the same
EndpointFilter do NOT conform the compatibility rule defined in
Table 1 of Section 8.1, an ALTO server MUST return an ALTO error
response with the error code "E_INVALID_FIELD_VALUE".
An ALTO client MUST specify either "endpoints" or "endpoint-flows",
but MUST NOT specify both in the same query.
6.3. Examples
6.3.1. Information Resource Directory
GET /directory HTTP/1.1
Host: alto.example.com
Accept: application/alto-directory+json,application/alto-error+json
HTTP/1.1 200 OK
Content-Length: [TODO]
Content-Type: application/alto-directory+json
{
"meta" : {
"default-alto-network-map" : "my-default-network-map",
"cost-types" : {
"num-routingcost" : {
"cost-mode" : "numerial",
"cost-metric" : "routingcost"},
"ord-routingcost" : {
"cost-mode" : "ordinal",
"cost-metric" : "routingcost"}
},
.....
Other ALTO cost types as described in RFC7285
.....
},
"resources" : {
"my-default-network-map" : {
"uri" : "http://alto.example.com/networkmap",
"media-type" : "application/alto-networkmap+json"
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},
"basic-flow-based-cost-map" : {
"uri" : "http://alto.example.com/costmap/multi/filtered",
"media-type" : "application/alto-costmap+json",
"accepts" : "application/alto-costmapfilter+json",
"uses" : [ "my-default-network-map" ],
"capabilities" : {
"max-cost-types" : 2,
"flow-based-filter" : true,
"cost-type-names" : [ "ord-routingcost" , "num-routingcost" ]
}
},
"basic-flow-based-endpoint-cost" : {
"uri" : "http://alto.example.com/endpointcost/lookup",
"media-type" : "application/alto-endpointcost+json",
"accepts" : "application/alto-endpointcostparams+json",
"capabilities" : {
"protocols": ["tcp", "http"],
"flow-based-filter" : true,
"cost-type-names" : [ "ord-routingcost" , "num-routingcost" ]
}
},
"flow-cost-map": {
"uri" : "http://alto.example.com/flowcost/lookup",
"media-type" : "application/alto-flowcost+json",
"accepts" : "application/alto-flowcostparams+json",
"capabilities" : {
"or-required" : [ [ "ethernet:destination" ],
[ "ipv4:destination" ] ],
"optional" : [ "ethernet:source", "ethernet:destination",
"ipv4:source", "ipv4:destination",
"tcp:source", "tcp:destination"]
}
}
}
}
6.3.2. Flow-based Filtered Cost Map Service
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POST /costmap/multi/filtered HTTP/1.1
Host: alto.example.com
Accept: application/alto-costmap+json,application/alto-error+json
Content-Length: [TBD]
Content-Type: application/alto-costmapfilter+json
{
"cost-type": {
"cost-mode": "numerical",
"cost-metric": "routingcost"
},
"pid-flows": [
{ "srcs": ["PID1"], "dsts": ["PID2", "PID3"] },
{ "srcs": ["PID3"], "dsts": ["PID4"] }
]
}
HTTP/1.1 200 OK
Content-Length: [TBD]
Content-Type: application/alto-costmap+json
{
"meta": {
"dependent-vtags": [
{
"resource-id": "my-default-network-map",
"tag": "75ed013b3cb58f896e839582504f622838ce670f"
}
],
"cost-type": {
"cost-mode": "numerical",
"cost-metric": "routingcost"
}
},
"cost-map": {
"PID1": { "PID2": 100 },
"PID1": { "PID3": 20 },
"PID3": { "PID4": 80 }
}
}
6.3.3. Flow-based Endpoint Cost Service Example
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POST /endpointcost/lookup HTTP/1.1
Host: alto.example.com
Accept: application/alto-endpointcost+json,application/alto-error+json
Content-Length: [TBD]
Content-Type: application/alto-endpointcostparams+json
{
"cost-type": {
"cost-mode": "numerical",
"cost-metric": "hopcount"
},
"endpoint-flows": [
{ "srcs": ["ipv4:192.0.2.2"],
"dsts": ["ipv4:192.0.2.89", "http:cdn1.example.com"] },
{ "srcs": ["tcp:203.0.113.45:54321"],
"dsts": ["http:cdn1.example.com"] }
]
}
HTTP/1.1 200 OK
Content-Length: [TBD]
Content-Type: application/alto-endpointcost+json
{
"meta": {
"cost-type": {
"cost-mode": "numerical",
"cost-metric": "hopcount"
}
},
"endpoint-cost-map": {
"ipv4:192.0.2.2": {
"ipv4:192.0.2.89": 3,
"http:cdn1.example.com": 6
},
"tcp:203.0.113.45:54321": {
"http:cdn1.example.com": 10
}
}
}
7. Security Considerations
As discussed in Section 15.4 of [RFC7285], an ALTO server or a third
party who is able to intercept the flow-based cost query messages MAY
store and process the obtained information in order to analyze user
behaviors and communication patterns. Since flow-based cost queries
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MAY potentially provide more accurate information, an ALTO client
should be cognizant about the trade-off between redundancy and
privacy.
8. IANA Considerations
This document defines new address types to be registered to an
existing ALTO registry, and a new registry for their compatible
address types.
8.1. ALTO Address Type Registry
This document defines several new address types to be registered to
ALTO Address Type Registry, listed in Table 1.
+------------+--------------------+-------------+-------------------+
| Identifier | Address Encoding | Prefix | Mapping to/from |
| | | Encoding | IPv4/v6 |
+------------+--------------------+-------------+-------------------+
| eth | See Section 5.2.1 | None | Mapping to/from |
| | | | IPv4 by [RFC0903] |
| | | | and [RFC0826]; |
| | | | Mapping to/from |
| | | | IPv6 by [RFC3122] |
| | | | and [RFC4861] |
| domain | See Section 5.2.2 | None | Mapping to/from |
| | | | IPv4 by [RFC1034] |
| domain6 | See Section 5.2.2 | None | Mapping to/from |
| | | | IPv6 by [RFC3596] |
| tcp | See Section 5.2.3 | None | No mapping |
| tcp6 | See Section 5.2.4 | None | No mapping |
| upd | See Section 5.2.3 | None | No mapping |
| udp6 | See Section 5.2.4 | None | No mapping |
+------------+--------------------+-------------+-------------------+
Table 1: ALTO Address Type Registry
8.2. ALTO Address Type Compatibility Registry
This document proposes to create a new registry called ALTO Address
Type Compatibility Registry, whose purpose is stated in Section 5.3.
The compatible address type identifiers of the ones registered in the
ALTO Address Type Registry are listed in Table 2.
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+-------------+-------------------------+
| Identifier | Compatible Identifiers |
+-------------+-------------------------+
| eth | ipv4, ipv6 |
| domain | eth, ipv4 |
| domain6 | eth, ipv6 |
| tcp | eth, ipv4, domain |
| tcp6 | eth, ipv6, domain6 |
| udp | eth, ipv4, domain |
| udp6 | eth, ipv6, domain6 |
+-------------+-------------------------+
Table 2: ALTO Address Type Compatibility Registry
The entry of an address type identifier SHOULD only include the
identifiers registered before it. The compatibility between address
types are bidirectional. For example, although "eth" does not
register "tcp" as its compatible identifier, an ALTO server MUST
recognize them as compatible because eth is registered as a
compatible identifier of "tcp".
Any new ALTO address type identifier registered after this document
MUST register their compatible identifiers in this registry
simultaneously.
9. Acknowledgment
The authors would like to thank Dawn Chen, Haizhou Du, Sabine
Randriamasy and Wendy Roome for their fruitful discussions and
feedback on this document. Shawn Lin also gave substantial review
feedback and suggestions on the protocol design.
10. References
10.1. Normative References
[RFC0826] Plummer, D., "Ethernet Address Resolution Protocol: Or
Converting Network Protocol Addresses to 48.bit Ethernet
Address for Transmission on Ethernet Hardware", STD 37,
RFC 826, DOI 10.17487/RFC0826, November 1982,
<https://www.rfc-editor.org/info/rfc826>.
[RFC0903] Finlayson, R., Mann, T., Mogul, J., and M. Theimer, "A
Reverse Address Resolution Protocol", STD 38, RFC 903,
DOI 10.17487/RFC0903, June 1984, <https://www.rfc-
editor.org/info/rfc903>.
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[RFC1034] Mockapetris, P., "Domain names - concepts and facilities",
STD 13, RFC 1034, DOI 10.17487/RFC1034, November 1987,
<https://www.rfc-editor.org/info/rfc1034>.
[RFC2119] Bradner, S., "Key words for use in RFCs to Indicate
Requirement Levels", BCP 14, RFC 2119,
DOI 10.17487/RFC2119, March 1997, <https://www.rfc-
editor.org/info/rfc2119>.
[RFC2181] Elz, R. and R. Bush, "Clarifications to the DNS
Specification", RFC 2181, DOI 10.17487/RFC2181, July 1997,
<https://www.rfc-editor.org/info/rfc2181>.
[RFC2732] Hinden, R., Carpenter, B., and L. Masinter, "Format for
Literal IPv6 Addresses in URL's", RFC 2732,
DOI 10.17487/RFC2732, December 1999, <https://www.rfc-
editor.org/info/rfc2732>.
[RFC3122] Conta, A., "Extensions to IPv6 Neighbor Discovery for
Inverse Discovery Specification", RFC 3122,
DOI 10.17487/RFC3122, June 2001, <https://www.rfc-
editor.org/info/rfc3122>.
[RFC3596] Thomson, S., Huitema, C., Ksinant, V., and M. Souissi,
"DNS Extensions to Support IP Version 6", STD 88,
RFC 3596, DOI 10.17487/RFC3596, October 2003,
<https://www.rfc-editor.org/info/rfc3596>.
[RFC3986] Berners-Lee, T., Fielding, R., and L. Masinter, "Uniform
Resource Identifier (URI): Generic Syntax", STD 66,
RFC 3986, DOI 10.17487/RFC3986, January 2005,
<https://www.rfc-editor.org/info/rfc3986>.
[RFC4861] Narten, T., Nordmark, E., Simpson, W., and H. Soliman,
"Neighbor Discovery for IP version 6 (IPv6)", RFC 4861,
DOI 10.17487/RFC4861, September 2007, <https://www.rfc-
editor.org/info/rfc4861>.
10.2. Informative References
[EUI48] IEEE, , "Guidelines for use of a 48-bit Extended Unique
Identifier (EUI-48)", 2012,
<http://standards.ieee.org/develop/regauth/tut/eui48.pdf>.
[EUI64] IEEE, , "Guidelines for use of a 64-bit Extended Unique
Identifier (EUI-64)", November 2012,
<http://standards.ieee.org/develop/regauth/tut/eui64.pdf>.
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[OF15] Foundation, O., "OpenFlow Switch Specification v1.5.0",
2014,
<https://www.opennetworking.org/images/stories/downloads/
sdn-resources/onf-specifications/openflow/openflow-switch-
v1.5.0.noipr.pdf>.
[OPENFLOW]
McKeown, N., Anderson, T., Balakrishnan, H., Parulkar, G.,
Peterson, L., Rexford, J., Shenker, S., and J. Turner,
"OpenFlow: enabling innovation in campus networks", 2008.
[RFC7159] Bray, T., Ed., "The JavaScript Object Notation (JSON) Data
Interchange Format", RFC 7159, DOI 10.17487/RFC7159, March
2014, <https://www.rfc-editor.org/info/rfc7159>.
[RFC7285] Alimi, R., Ed., Penno, R., Ed., Yang, Y., Ed., Kiesel, S.,
Previdi, S., Roome, W., Shalunov, S., and R. Woundy,
"Application-Layer Traffic Optimization (ALTO) Protocol",
RFC 7285, DOI 10.17487/RFC7285, September 2014,
<https://www.rfc-editor.org/info/rfc7285>.
[RFC8189] Randriamasy, S., Roome, W., and N. Schwan, "Multi-Cost
Application-Layer Traffic Optimization (ALTO)", RFC 8189,
DOI 10.17487/RFC8189, October 2017, <https://www.rfc-
editor.org/info/rfc8189>.
Authors' Addresses
Jingxuan Jensen Zhang
Tongji University
4800 Cao'an Hwy
Shanghai 201804
China
Email: jingxuan.n.zhang@gmail.com
Kai Gao
Tsinghua University
30 Shuangqinglu Street
Beijing 100084
China
Email: gaok12@mails.tsinghua.edu.cn
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Junzhuo Austin Wang
Tongji University
4800 Cao'an Hwy, Jiading District
Shanghai
China
Email: wangjunzhuo200@gmail.com
Qiao Xiang
Tongji/Yale University
51 Prospect Street
New Haven, CT
USA
Email: qiao.xiang@cs.yale.edu
Y. Richard Yang
Yale University
51 Prospect St
New Haven CT
USA
Email: yry@cs.yale.edu
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