Network Working Group
Internet Engineering Task Force (IETF) O. Finkelman
Internet-Draft
Request for Comments: 8804 Qwilt
Intended status:
Category: Standards Track S. Mishra
Expires: May 23, 2020
ISSN: 2070-1721 Verizon
November 20, 2019
CDNI
September 2020
Content Delivery Network Interconnection (CDNI) Request Routing
Extensions
draft-ietf-cdni-request-routing-extensions-08
Abstract
Open Caching architecture is a use case of Content Delivery Networks Network
Interconnection (CDNI) in which the commercial Content Delivery
Network (CDN) is the upstream CDN (uCDN) and the ISP caching layer
serves as the downstream CDN (dCDN). The extensions specified in
this This document defines
extensions to the CDNI Metadata Interface (MI) and the Footprint
and &
Capabilities Interface (FCI) Advertisement interface (FCI). These extensions are
derived from requirements raised by Open Caching but are also
applicable to CDNI use cases in general.
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 an Internet Standards Track document.
This document is a product of the Internet Engineering Task Force
(IETF). Note that other groups may also distribute
working documents as Internet-Drafts. The list It represents the consensus of current Internet-
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Internet-Drafts are draft documents valid the IETF community. It has
received public review and has been approved for a maximum publication by the
Internet Engineering Steering Group (IESG). Further information on
Internet Standards is available in Section 2 of six months RFC 7841.
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material or to cite them other than as "work in progress."
This Internet-Draft will expire on May 23, 2020.
https://www.rfc-editor.org/info/rfc8804.
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document authors. All rights reserved.
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Table of Contents
1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 2
1.1. Terminology . . . . . . . . . . . . . . . . . . . . . . . 3
1.2. Requirements Language . . . . . . . . . . . . . . . . . . 3
2. Redirect Target Capability . . . . . . . . . . . . . . . . . 4
2.1. DNS Redirect Target . . . . . . . . . . . . . . . . . . . 5
2.2. HTTP Redirect Target . . . . . . . . . . . . . . . . . . 5
2.3. Properties of Redirect Target Capability Object . . . . . 5
2.4. DnsTarget Object . . . . . . . . . . . . . . . . . . . . 7
2.4.1. DNS Target DnsTarget Example . . . . . . . . . . . . . . . . . 7
2.5. HttpTarget Object . . . . . . . . . . . . . . . . . . . . 8
2.5.1. HTTP Target HttpTarget Example . . . . . . . . . . . . . . . . . 9
2.6. Usage Example . . . . . . . . . . . . . . . . . . . . . . 10
3. Fallback Target Server Address Metadata . . . . . . . . . . . . . . 11
3.1. Properties of Fallback Target Address Generic Metadata Object . . 12
3.2. Usage Example . . . . . . . . . . . . . . . . . . . . . . 13
3.3. uCDN addressing considerations . . . . . . . . . . . . . 15 Addressing Considerations
4. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 16
4.1. CDNI Payload Types . . . . . . . . . . . . . . . . . . . 16
4.1.1. CDNI FCI RedirectTarget Payload Type . . . . . . . . 16
4.1.2. CDNI MI FallbackTarget Payload Type . . . . . . . . . 16
5. Security Considerations . . . . . . . . . . . . . . . . . . . 17
5.1. Confidentiality and Privacy . . . . . . . . . . . . . . . 17
6. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . 17
7. References . . . . . . . . . . . . . . . . . . . . . . . . . 17
7.1.
6.1. Normative References . . . . . . . . . . . . . . . . . . 17
7.2.
6.2. Informative References . . . . . . . . . . . . . . . . . 18
Acknowledgements
Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 19
1. Introduction
The Streaming Video Alliance [SVA] is a global association that works
to solve streaming video challenges in an effort to improve end-user
experience and adoption. The Open Caching Working Group [OCWG] of
the Streaming Video Alliance [SVA] is focused on the delegation of
video delivery requests from commercial CDNs to a caching layer at
the Internet Service Provider's (ISP) ISP's network. Open Caching architecture is a specific use case
of CDNI where the commercial CDN is the upstream CDN (uCDN) and the
ISP caching layer is the downstream CDN (dCDN). The Open Caching
Request Routing Functional Specification [OC-RR] defines the Request
Routing process and the interfaces that are required for its
provisioning. This document defines and registers the CDNI metadata object
[RFC8006] and the CDNI Footprint and Capabilities object [RFC8008]
that are required for Open Caching Request Routing. Routing:
* Redirect Target Capability (for dCDN advertising redirect target
address)
* Fallback Target Metadata (for uCDN configuring fallback target
address)
This document also registers CDNI Payload Types [RFC7736] for these
defined objects.
For consistency with other CDNI
documents documents, this document follows the
CDNI convention of uCDN (upstream CDN) and dCDN (downstream CDN) to
represent the commercial CDN and ISP caching layer layer, respectively.
This document also registers CDNI Payload Types [RFC7736] for the
defined objects:
o Redirect Target Capability (for dCDN advertising redirect target
address)
o Fallback Target Metadata (for uCDN configuring fallback target
address)
1.1. Terminology
The following terms are used throughout this document:
o
FQDN - Fully Qualified Domain Name
o
CDN - Content Delivery Network
Additionally, this document reuses the terminology defined in
[RFC6707], [RFC7336], [RFC8006], [RFC8007], and [RFC8008].
Specifically, we use the following CDNI acronyms:
o
FCI - Footprint and Capability Interface & Capabilities Advertisement interface (see
[RFC8008])
o
MI - Metadata Interface (see [RFC8006])
o uCDN, dCDN -
uCDN Upstream CDN and (see [RFC7336])
dCDN Downstream CDN respectively (see [RFC7336])
o
RT - Redirection Target. Endpoint for redirection from uCDN to
dCDN.
o
RR - Request Router. An element responsible for routing user
requests, typically using HTTP redirect or DNS CNAME,
depending on the use case.
1.2. Requirements Language
The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT",
"SHOULD", "SHOULD NOT", "RECOMMENDED", "NOT RECOMMENDED", "MAY", and
"OPTIONAL" in this document are to be interpreted as described in
BCP 14 [RFC2119] [RFC8174] when, and only when, they appear in all
capitals, as shown here.
2. Redirect Target Capability
Iterative request redirection CDNI Request Redirection is defined in Section 1.1 of
[RFC7336] and elaborated by examples in Sections 3.2 and 3.4 of
[RFC7336]. A Redirection Target (RT) is defined in Section 2 of
[RFC7975] for Recursive Request Redirection as:
"The
| The endpoint to which the User Agent is redirected. In CDNI, a an
| RT may point to a number of different components, some examples
| include a surrogate in the same CDN as the request router, a
| request router in a dCDN, or a surrogate in a dCDN". dCDN.
In this document document, we adopt the same definition of the RT for the
Iterative Request Redirect use case. This use case requires the
provisioning of the RT address to be used by the uCDN in order to
redirect to the dCDN. RT addresses can vary between different
footprints, for
footprints (for example, between different regions, regions), and they may
also change over time, for example time (for example, as a result of network problems. problems).
Given this variable and dynamic nature of the redirect target
address, it may not be suitable to advertise it during bootstrap. A
more dynamic and footprint oriented footprint-oriented interface is required.
Section 4.3 of [RFC7336] suggests that it could be one of the roles
of the FCI [RFC8008]. Following this suggestion, we have therefore, therefore
chosen to use the CDNI Footprint and & Capabilities Advertisement
interface for redirect target address advertisement.
Use cases
o cases:
* Footprint: The dCDN may want to have a different target per
footprint. Note that a dCDN may spread across multiple
geographies. This makes it easier to route client requests to a
nearby request router. Though this can be achieved using a single
canonical name and "Geo DNS", such that in different geographies
the same hostname is resolved to different IP address, that
approach has limitations; for example example, a client may be using a
third party
third-party DNS resolver, making it impossible for the redirector
to detect where the client is located, or Geo DNS granularity may
be too rough for the requirement of the application.
o
* Scaling: The dCDN may choose to scale its request routing Request Routing service
by deploying more request routers in new locations and advertise
them via an updatable interface like the FCI.
The Redirect Target capability object is used to indicate the target
address the uCDN should use in order to redirect a client to the
dCDN. A target may be attached to a specific uCDN host, attached to
a list of uCDN hosts, or used globally for all the hosts of the uCDN.
When a dCDN is attaching the redirect target to a specific uCDN host
or a list of uCDN hosts, the dCDN MUST advertise the hosts within the
Redirect Target capability object as "redirecting-hosts". In this
case, the uCDN can redirect to that dCDN address, only if the User
Agent request was to one of these uCDN hosts.
If the redirect target Redirect Target capability object does not contain a target or
the target is empty, the uCDN MUST interpret it as "no target
available for these uCDN hosts for the specified footprint". In case
such a target was already advertised in a previous FCI object, the
uCDN MUST interpret it as an update that deletes the previous
redirect target.
2.1. DNS Redirect Target
A redirect target for DNS redirection is a an FQDN used as an alias in
a CNAME record response (see [RFC1034]) of the uCDN DNS router. Note
that DNS routers make routing decisions based on either the DNS
resolver's IP address or the client IP subnet when EDNS0 client-
subnet (ECS) is used (see [RFC7871]). The dCDN may choose to
advertise redirect targets and footprints to cover both cases, such
that the uCDN resolution would route the DNS query to a different dCDN
CNAMEs according to client subnet or dCDN resolver IP address. This
method further allows the dCDN DNS to optimize the resolution by
localizing the target CNAMEs. A uCDN implementation SHOULD prefer
routing based on client IP subnet when the ECS option is present. A
dCDN implementation using the ECS option MUST be aware of the privacy
drawbacks listed in Section 2 of [RFC7871] and SHOULD follow the
guidelines provided in Section 11.1 of [RFC7871].
2.2. HTTP Redirect Target
A redirect target for HTTP redirection is the URI to be used as the
value for the Location header of a an HTTP redirect 3xx response,
typically a 302 (Found) (see Section 7.1.2 of [RFC7231] and section
Section 6.4 of [RFC7231]).
2.3. Properties of Redirect Target Capability Object
The Redirect Target capability object consists of the following
properties:
Property: redirecting-hosts
Description: One or more uCDN hosts to which this redirect target
is attached. A redirecting host SHOULD be a host that was
published in a HostMatch object by the uCDN as defined in
Section 4.1.2 of [RFC8006].
Type: A list of Endpoint objects (see Section 4.3.3 of [RFC8006])
Mandatory-to-Specify: No. If not present, absent or empty, the redirect
target applies to all hosts of the redirecting uCDN.
Property: dns-target
Description:
Target CNAME record for DNS redirection.
Type:
DnsTarget object (see Section 2.4)
Mandatory-to-Specify:
No. If the dns-target is not present absent or
empty empty, the uCDN MUST
interpret it as "no dns-target available".
Property: http-target
Description:
Target URI for a an HTTP redirect.
Type:
HttpTarget object (see Section 2.5)
Mandatory-to-Specify:
No. If the http-target is not present absent or
empty empty, the uCDN MUST
interpret it as "no http-target available".
The following is an example of a Redirect Target capability object
serialization that advertises a dCDN target address that is attached
to a specific list of uCDN "redirecting-hosts". A uCDN host that is
included in that list can redirect to the advertised dCDN redirect
target. The capabilities object is serialized as a JSON object as
defined in Section 5.1 of [RFC8008] [RFC8008].
{
"capabilities": [
{
"capability-type": "FCI.RedirectTarget",
"capability-value": {
"redirecting-hosts": [
"a.service123.ucdn.example.com",
"b.service123.ucdn.example.com"
],
"dns-target": {
"host": "service123.ucdn.dcdn.example.com"
},
"http-target": {
"host": "us-east1.dcdn.example.com",
"path-prefix": "/cache/1/",
"include-redirecting-host": true
}
},
"footprints": [
<Footprint objects>
]
}
]
}
2.4. DnsTarget Object
The DnsTarget object gives the target address for the DNS response to
delegate from the uCDN to the dCDN.
Property: host
Description: The host property is a hostname or an IP address,
without a port number.
Type: Endpoint object as defined in Section 4.3.3 of [RFC8006] [RFC8006],
with the limitation that it SHOULD NOT include a port number
and, in case a port number is present, the uCDN MUST ignore it.
Mandatory-to-Specify: Yes.
2.4.1. DNS Target DnsTarget Example
The following is an example of the DnsTarget object:
{
"host": "service123.ucdn.dcdn.example.com"
}
The following is an example of a DNS query for uCDN address
"a.service123.ucdn.example.com" and the corresponding CNAME
redirection response:
Query:
a.service123.ucdn.example.com:
type A, class IN
Response:
NAME: a.service123.ucdn.example.com, TYPE: CNAME, CLASS: IN,
TTL: 120, RDATA: service123.ucdn.dcdn.example.com
2.5. HttpTarget Object
The HttpTarget object gives the necessary information to construct
the target Location URI for HTTP redirection.
Property: host
Description: Hostname or IP address and an optional port, i.e.,
the host and port of the authority component of the URI as
described in Section 3.2 of [RFC3986].
Type: Endpoint object as defined in Section 4.3.3 of [RFC8006].
Mandatory-to-Specify: Yes.
Property: scheme
Description: A URI scheme to be used in the redirect response
location construction. When present, the uCDN MUST use the
provided scheme in for HTTP redirection to the dCDN.
Type: A URI scheme as defined in Section 3.1 of [RFC3986] [RFC3986],
represented as a JSON string. The scheme MUST be either "http"
or "https".
Mandatory-to-Specify: No. If this property is absent or empty empty,
the uCDN request router MUST use the same scheme as was used in
the original request before redirection.
Property: path-prefix
Description: A path prefix for the HTTP redirect Location header.
The original path is appended after this prefix.
Type: A prefix of a path-absolute as defined in Section 3.3 of
[RFC3986]. The prefix MUST end with a trailing slash, slash to
indicate the end of the last path segment in the prefix.
Mandatory-to-Specify: No. If this property is absent or empty,
the uCDN MUST NOT prepend a path prefix path-prefix to the original content
path, i.e., the original path MUST appear in the location Location URI
right after the authority component.
Property: include-redirecting-host
Description: A flag indicating whether or not to include the
redirecting host as the first path segment after the path-
prefix. If set to true and a "path-prefix" is used, the uCDN
redirecting host MUST be added as a separate path segment after
the path-prefix and before the original URL path. If set to
true and there is no path-prefix, the uCDN redirecting host
MUST be prepended as the first path segment in the redirect
URL.
Type: Boolean.
Mandatory-to-Specify: No. Default value is False.
2.5.1. HTTP Target Example HttpTarget Example
The following is an example of the HttpTarget object with a "scheme",
a "path-prefix", and "include-redirecting-host" properties:
{
"host": "us-east1.dcdn.example.com",
"scheme": "https",
"path-prefix": "/cache/1/",
"include-redirecting-host": true
}
Example
The following is an example of a an HTTP request for content at uCDN
host "a.service123.ucdn.example.com" and the corresponding HTTP
response with a Location header, used for redirecting the client to
the dCDN, constructed according to the HttpTarget object from the
above example:
Request:
GET /vod/1/movie.mp4 HTTP/1.1
Host: a.service123.ucdn.example.com
Response:
HTTP/1.1 302 Found
Location: https://us-east1.dcdn.example.com/cache/1/
a.service123.ucdn.example.com/vod/1/movie.mp4
2.6. Usage Example
Before requests can be routed from the uCDN to the dCDN dCDN, the CDNs
must exchange service configurations between them. Using the MI, the
uCDN advertises out-of-band its hosts to the dCDN, dCDN; each host is
designated by a hostname and has its own specific metadata (see
Section 4.1.2 of
[RFC8006]. The dCDN, using [RFC8006]). Using the FCI, advertises, also out-of-band, the dCDN advertises
(also out-of-band) the redirect target address object defined in Section 2.3
for the relevant uCDN hosts. The following is a generalized example
of the message flow between an upstream CDN a uCDN and a downstream dCDN. For simplicity, we
focus on the sequence of messages between the uCDN and dCDN and not
on how they are passed.
dCDN uCDN
+ +
| |
(1) | MI: host: s123.ucdn.example.com |
| host-metadata: < metadata > |
<-------------------------------------------------------+
| |
(2) | FCI: capability-type: FCI.RedirectTarget |
| redirecting-hosts: s123.ucdn.example.com |
| target host: us-east1.dcdn.example.com |
+------------------------------------------------------->
| |
| |
+ +
Figure 1: Redirect target address advertisement
1. Target Address Advertisement
Explanation:
(1) The uCDN advertises a host (s123.ucdn.example.com) with the host
metadata.
2.
(2) The dCDN advertises its FCI objects to the uCDN uCDN, including a
FCI.RedirectTarget
Redirect Target capability object that contains the redirect
target address (us-east1.dcdn.example.com) specified for that
uCDN host.
Once the redirect target has been set, the uCDN can start redirecting
user requests to the dCDN. The following is a generic sequence of
redirection using the host and redirect target that were advertised
in Figure 1 above. 1.
End User dCDN uCDN RR
+ + +
| | |
(1) | Request sent s123.ucdn.example.com |
+-----------------------+----------------------->
| | |
(2) | Redirect to us-east1.dcdn.example.com |
<-----------------------+-----------------------+
| | |
(3) | Request us-east1.dcdn.example.com |
+-----------------------> |
| | |
(4) | Response | |
<-----------------------+ |
| | |
+ + +
Figure 2: Generic requests redirection sequence
1. Request Redirection Sequence
Explanation:
(1) The End User sends a request (DNS or HTTP) to the uCDN Request
Router (RR).
2.
(2) Using the previously advertised Redirect Target, the uCDN
redirects the request to the dCDN.
3.
(3) The End User sends a request to the dCDN.
4.
(4) The dCDN either sends a response or reroutes it, for example, to
a dCDN surrogate.
3. Fallback Target Server Address Metadata
Open Caching requires that the uCDN provides a fallback target server
to the dCDN, dCDN to be used in cases where the dCDN cannot properly handle
the request. To avoid redirect loops, the fallback target server's
address at the uCDN MUST be different from the original uCDN address
from which the client was redirected to the dCDN. The uCDN MUST
avoid further redirection when receiving the client request at the
fallback target. The fallback target Fallback Target is defined as a generic
metadata object (see Section 3.2 of [RFC8006]) [RFC8006]).
Use cases
o cases:
* Failover: A dCDN request router receives a request but has no
caches to which it can route the request. This can happen in the
case of failures or temporary network overload.
o
* No coverage: A dCDN request router receives a request from a
client located in an area inside the footprint but not covered by
the dCDN caches or outside the dCDN footprint coverage. In such
cases, the router may choose to redirect the request back to the
uCDN fallback address.
o
* Error: A cache may receive a request that it cannot properly
serve, for example, some of the metadata objects for that service
were not properly acquired. In this case, the cache's "default
action" may be to "redirect back to uCDN".
The Fallback target Target metadata object is used to indicate the target
address the dCDN should redirect a client to when falling back to the
uCDN. Fallback The fallback target address is represented as an endpoint Endpoint
object as defined in Section 4.3.3 of [RFC8006].
In DNS redirection redirection, a CNAME record is used as the fallback target
address.
In HTTP redirection redirection, a hostname is used as the fallback target
address.
When using HTTP redirect to route a client request back to the uCDN,
it is the dCDN's responsibility to use the original URL path as the
client would have used for the original uCDN request, stripping, if
needed, the dCDN path-prefix and/or the uCDN hostname from the
redirect URL that may have been used to request the content from the
dCDN.
3.1. Properties of Fallback Target Address Generic Metadata Object
The MI.FallbackTarget Metadata generic metadata object consists of the
following
single property: two properties:
Property: host
Description: Target address to which the dCDN can redirect the
client.
Type: Endpoint object as defined in Section 4.3.3 of [RFC8006] [RFC8006],
with the limitation that in case of DNS delegation delegation, it SHOULD
NOT include a port number and, number, and in case a port number is
present, the dCDN MUST ignore it.
Mandatory-to-Specify: Yes.
Property: scheme
Description: A URI scheme to be used in the redirect response
location construction. When present, the dCDN MUST use this
scheme in case of HTTP redirection to the uCDN fallback
address.
Type: A URI scheme as defined in Section 3.1 of [RFC3986] [RFC3986],
represented as a JSON string. The scheme MUST be either "http"
or "https".
Mandatory-to-Specify: No. In case of HTTP redirection to
fallback, if this property is absent or empty, the dCDN
redirecting entity MUST use the same scheme as in the request
received by the dCDN.
Example
The following is an example of a an MI.FallbackTarget Metadata generic metadata
object that designates the host address the dCDN should use as
fallback address to redirect back to the uCDN. uCDN:
{
"generic-metadata-type": "MI.FallbackTarget",
"generic-metadata-value":
{
"host": "fallback-a.service123.ucdn.example",
"scheme": "https"
}
}
3.2. Usage Example
The uCDN advertises out-of-band the fallback target address to the
dCDN, so that the dCDN may redirect a request back to the uCDN in
case the dCDN cannot serve it. Using the MI MI, the uCDN advertises its
hosts to the dCDN, along with their specific host metadata (see
Section 4.1.2 of [RFC8006]. [RFC8006]). The Fallback Target generic metadata
object is encapsulated within the "host-metadata" property of each
host. The following is an example of a message flow between an
upstream CDN a uCDN
and a downstream dCDN. For simplicity, we focus on the sequence of messages
between the uCDN and dCDN, not on how they are passed.
dCDN uCDN
+ +
| |
(1) | MI: host: s123.ucdn.example.com |
| host-metadata: |
| < metadata objects > |
| < MI.FallbackTarget |
| host: fallback-a.service123.ucdn.example > |
| < metadata objects > |
<-------------------------------------------------------+
| |
(2) | FCI: capability-type: FCI.RedirectTarget |
| redirecting-hosts: s123.ucdn.example.com |
| target host: us-east1.dcdn.example.com |
+------------------------------------------------------->
| |
| |
+ +
Figure 3: Advertisement of host metadata Host Metadata with Fallback Target
1.
Explanation:
(1) The uCDN advertises a host (s123.ucdn.example.com) with the host
metadata. The host-metadata property contains a an
MI.FallbackTarget generic metadata object.
2.
(2) The dCDN advertises its FCI objects to the uCDN uCDN, including a
FCI.RedirectTarget
Redirect Target capability object that contains the redirect
target address (us-east1.dcdn.example.com) specified for that
uCDN host.
The following is a generic sequence of redirection using the
configurations that were advertised in Figure 3 above. 3. In this case case, the
dCDN redirects back to the uCDN fallback target address.
End User dCDN uCDN fallback uCDN RR
+ + + +
| | | |
(1) | Request sent s123.ucdn.example.com | |
+-------------------+-------------------+------------------->
| | | |
(2) | Redirect to us-east1.dcdn.example.com | |
<-------------------+-------------------+-------------------+
| | | |
(3) | Request us-east1.dcdn.example.com | |
+-------------------> | |
| | | |
(4) | Redirect back to fallback-a.service123.ucdn.example |
<-------------------+ | |
| | | |
(5) | Request fallback-a.service123.ucdn.example |
+---------------------------------------> |
| | | |
(6) | Response | | |
<-------------------+-------------------+ |
| | | |
+ + + +
Figure 4: Redirection to Fallback Target
1.
Explanation:
(1) The End User sends a request (DNS or HTTP) to the uCDN Request
Router (RR).
2.
(2) Using the previously advertised Redirect Target, the uCDN
redirects the request to the dCDN.
3.
(3) The End User sends a request to the dCDN.
4.
(4) The dCDN cannot handled handle the request and, therefore, and therefore redirects it
back to the uCDN fallback target address.
5.
(5) The End User sends the request to the uCDN fallback target
address.
6.
(6) The uCDN either sends a response or reroutes it, for example, to
a uCDN surrogate.
3.3. uCDN addressing considerations Addressing Considerations
When advertising fallback addresses to the dCDN dCDN, the uCDN SHOULD
consider the failure use cases that may lead the dCDN to route
requests to uCDN fallback. In extreme dCDN network failures or under
denial-of-service (DoS) attacks, requests coming from a large segment
or multiple segments of the dCDN may be routed back to the uCDN. The
uCDN SHOULD therefore design its fallback addressing scheme and its
available resources accordingly. A favorable approach would be for
the uCDN to use a different fallback target address for each uCDN
host, enabling it to load balance the requests using the same methods
as it would for its original hosts. See Sections 4.1.2 and 4.1.3 of
[RFC8006] for a detailed description of how to use GenericMetadata
objects within the HostMatch object advertised in the HostIndex of
the uCDN.
4. IANA Considerations
4.1. CDNI Payload Types
This document requests the registration of
IANA has registered the following CDNI Payload Types under in the IANA "CDNI
Payload Types" registry defined in [RFC7736]:
+--------------------+---------------+
+====================+===============+
| Payload Type | Specification |
+--------------------+---------------+
+====================+===============+
| FCI.RedirectTarget | RFCthis RFC 8804 |
+--------------------+---------------+
| MI.FallbackTarget | RFCthis RFC 8804 |
+--------------------+---------------+
[RFC Editor: Please replace RFCthis with the published RFC number for
this document.]
Table 1
4.1.1. CDNI FCI RedirectTarget Payload Type
Purpose: The purpose of this payload type is to distinguish
RedirectTarget FCI
advertisement objects for redirect target.
Interface: FCI
Encoding: see See Section 2.3 2.3.
4.1.2. CDNI MI FallbackTarget Payload Type
Purpose: The purpose of this payload type is to distinguish
FallbackTarget MI objects (and any associated capability
advertisement)
advertisement).
Interface: MI/FCI
Encoding: see See Section 3.1 3.1.
5. Security Considerations
This specification is in accordance with defines extensions to the CDNI Metadata Interface
(MI) and the CDNI Request Routing: Footprint and & Capabilities Semantics. Advertisement interface (FCI).
As such, it is subject to the security and privacy considerations as
defined in Section 8 of [RFC8006] and in Section 7 of [RFC8008] [RFC8008],
respectively.
5.1. Confidentiality and Privacy
The Redirect Target FCI capability object potentially reveals information
about the internal structure of the dCDN network. A third party
could intercept the FCI transactions and use the information to
attack the dCDN. The same is also true for the Fallback Target Metadata object
generic metadata object, as it may reveal information about the
internal structure of the uCDN, exposing it to external exploits.
Implementations of the FCI and MI MUST therefore use strong
authentication and encryption and strictly follow the directions for
securing the interface as defined for the Metadata Interface in
Section 8.3 of [RFC8006].
6.
7. References
7.1.
6.1. Normative References
[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>.
[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>.
[RFC6707] Niven-Jenkins, B., Le Faucheur, F., and N. Bitar, "Content
Distribution Network Interconnection (CDNI) Problem
Statement", RFC 6707, DOI 10.17487/RFC6707, September
2012, <https://www.rfc-editor.org/info/rfc6707>.
[RFC7231] Fielding, R., Ed. and J. Reschke, Ed., "Hypertext Transfer
Protocol (HTTP/1.1): Semantics and Content", RFC 7231,
DOI 10.17487/RFC7231, June 2014,
<https://www.rfc-editor.org/info/rfc7231>.
[RFC7336] Peterson, L., Davie, B., and R. van Brandenburg, Ed.,
"Framework for Content Distribution Network
Interconnection (CDNI)", RFC 7336, DOI 10.17487/RFC7336,
August 2014, <https://www.rfc-editor.org/info/rfc7336>.
[RFC7975] Niven-Jenkins, B., Ed. and R. van Brandenburg, Ed.,
"Request Routing Redirection Interface for Content
Delivery Network (CDN) Interconnection", RFC 7975,
DOI 10.17487/RFC7975, October 2016,
<https://www.rfc-editor.org/info/rfc7975>.
[RFC8006] Niven-Jenkins, B., Murray, R., Caulfield, M., and K. Ma,
"Content Delivery Network Interconnection (CDNI)
Metadata", RFC 8006, DOI 10.17487/RFC8006, December 2016,
<https://www.rfc-editor.org/info/rfc8006>.
[RFC8007] Murray, R. and B. Niven-Jenkins, "Content Delivery Network
Interconnection (CDNI) Control Interface / Triggers",
RFC 8007, DOI 10.17487/RFC8007, December 2016,
<https://www.rfc-editor.org/info/rfc8007>.
[RFC8008] Seedorf, J., Peterson, J., Previdi, S., van Brandenburg,
R., and K. Ma, "Content Delivery Network Interconnection
(CDNI) Request Routing: Footprint and Capabilities
Semantics", RFC 8008, DOI 10.17487/RFC8008, December 2016,
<https://www.rfc-editor.org/info/rfc8008>.
[RFC8174] Leiba, B., "Ambiguity of Uppercase vs Lowercase in RFC
2119 Key Words", BCP 14, RFC 8174, DOI 10.17487/RFC8174,
May 2017, <https://www.rfc-editor.org/info/rfc8174>.
7.2.
6.2. Informative References
[OC-RR] Finkelman, O., Ed., Hofmann, J., Klein, E., Mishra, S.,
Ma, K., Sahar, D., and B. Zurat, "Open Caching - Cache Request
Routing Functional Specification", Version 1.1, October
2019, November
2016, <https://www.streamingvideoalliance.org/books/open-
cache-request-routing-functional-specification/>.
[OCWG] Streaming Video Alliance, "Open Caching Home Page", Caching",
<https://www.streamingvideoalliance.org/technical-groups/
open-caching/>.
[RFC7736] Ma, K., "Content Delivery Network Interconnection (CDNI)
Media Type Registration", RFC 7736, DOI 10.17487/RFC7736,
December 2015, <https://www.rfc-editor.org/info/rfc7736>.
[RFC7871] Contavalli, C., van der Gaast, W., Lawrence, D., and W.
Kumari, "Client Subnet in DNS Queries", RFC 7871,
DOI 10.17487/RFC7871, May 2016,
<https://www.rfc-editor.org/info/rfc7871>.
[SVA] "Streaming Video Alliance Home Page", Alliance",
<https://www.streamingvideoalliance.org>.
Acknowledgements
The authors thank Nir B. Sopher for reality checks against production
use cases, cases; his contribution is significant to this document. The
authors also thank Ben Niven-Jenkins for his review and feedback and
Kevin J. Ma for his guidance throughout the development of this
document
document, including his regular reviews.
Authors' Addresses
Ori Finkelman
Qwilt
6, Ha'harash
Hod HaSharon 4524079
Israel
Email: ori.finkelman.ietf@gmail.com
Sanjay Mishra
Verizon
13100 Columbia Pike
Silver Spring, MD 20904
USA
United States of America
Email: sanjay.mishra@verizon.com