Internet DRAFT - draft-tsuzaki-netconfig-webapi
draft-tsuzaki-netconfig-webapi
Network Working Group Y. Tsuzaki
Internet-Draft Kyoto University
Intended status: Informational R. Atarashi
Expires: March 12, 2016 IIJ Innovation Institute Inc.
S. Suzuki
Keio University
K. Mitsuya
K. Okada
Lepidum Co. Ltd.
September 09, 2015
Network configuration Web API for Bandwidth Reservation
draft-tsuzaki-netconfig-webapi-01.txt
Abstract
This draft introduces a framework for a dynamic bandwidth reservation
via Web API for Web applications. In this document, we propose Web
APIs for Web clients to request bandwidth allocation to network
controllers. The network controller could be both of SDN compliant
or Non-SDN compliant one. In this document, a network specification
definition language is also proposed.
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
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material or to cite them other than as "work in progress."
This Internet-Draft will expire on March 12, 2016.
Copyright Notice
Copyright (c) 2015 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
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Table of Contents
1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 2
2. Requirement . . . . . . . . . . . . . . . . . . . . . . . . . 3
3. Terminology . . . . . . . . . . . . . . . . . . . . . . . . . 3
4. System architecture . . . . . . . . . . . . . . . . . . . . . 4
4.1. Management server . . . . . . . . . . . . . . . . . . . . 4
4.2. Media client . . . . . . . . . . . . . . . . . . . . . . 5
4.3. Program Server . . . . . . . . . . . . . . . . . . . . . 5
4.4. Media Server . . . . . . . . . . . . . . . . . . . . . . 5
4.5. System components . . . . . . . . . . . . . . . . . . . . 6
5. API . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7
5.1. Service definition language . . . . . . . . . . . . . . . 7
5.2. Web API . . . . . . . . . . . . . . . . . . . . . . . . . 9
5.2.1. Resource usage report . . . . . . . . . . . . . . . . 9
5.2.2. Resource request . . . . . . . . . . . . . . . . . . 11
5.2.3. Keep-alive . . . . . . . . . . . . . . . . . . . . . 16
6. Security Considerations . . . . . . . . . . . . . . . . . . . 16
7. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 16
8. Acknowledgement . . . . . . . . . . . . . . . . . . . . . . . 16
9. References . . . . . . . . . . . . . . . . . . . . . . . . . 16
9.1. Normative References . . . . . . . . . . . . . . . . . . 16
9.2. Informative References . . . . . . . . . . . . . . . . . 17
Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 17
1. Introduction
This draft proposes a framework for a dynamic bandwidth reservation
via Web API for Web applications. We assume that there are network
controllers to control the network devices and gather information
about their control domain. Those controllers equip Web APIs so that
Web clients can request bandwidth allocated virtual private paths
between contents Web servers and the clients. Network administrators
describe the service specifications with "service description
language", and the bandwidth are allocated to the clients according
to the service specifications. This draft explains the overview of
this architecture and how resource reservations are made.
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2. Requirement
o From the Viewpoint of Network Administrators
Based on the service specifications configured by the
administrators, network management controllers automatically
respond to the client requests via Web APIs.
o From the Viewpoint of Clients
By accessing the Web API for the network resource reservations,
clients can reserve QoS guaranteed communication bandwidth for Web
contents downloads.
o Use Case
The network administrators prepare Web APIs for configuring
network paths and bandwidth reservations. When a client need to
download large contents from a Web server, the client send the
requiring resource information to the network management server
via Web APIs. The network management server construct a QoS
guaranteed communication path for the client based on the
information received from the client.
3. Terminology
o Service Description Language (SDL): A language by which
administrators describes network device information.
Administrators describe SDL and put the descriptions to management
servers.
o Network Description Language (NDL): A language by which
administrators describes network service information.
Administrators describe NDL and put the descriptions to management
servers.
o Management server: Servers which control the network devices in a
domain. These servers also provide the application interfaces for
media clients to signal resource requests. Administrators
describe the network configurations and policies of networks by
SDL/NDL and put them to management servers. Management servers
are also referred as Network management servers.
o Media server: Kind of a web server, which delivers media contents
to media clients.
o Media client: Client application run on a Web Browser, which
receives and present media contents to an end user.
o Service specification: The description of network service
components described by SDL/NDL.
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o Resource request: Action by which media clients obtain resource
reserved communication path to media servers.
4. System architecture
+----------------+
| Management |
Resource | server |
Request +-+---+-------+--+-+
+------> | WEB API | | |
| +---------+ | | Path
| | | Setup
| | |
| , - \+ +/- ,
| , ' \ / ' ,
| , \/ ,
+----+---+ +-------------------------------+ +--------+
| Media | Reserved | Media |
| client | Path | server |
+--------+ +-------------------------------+ +--------+
, SDN/Non-SDN ,
, BackBone ,
, , '
' + , _ _ _ , '
Figure 1: System Architecture
Figure 1 depicts the system overview of application triggered
resource reservation architecture. All the network components except
for the end clients in the domain (routers, servers) are under the
control of the management server. The network management server
gathers network management information such as status of network
devices or links in the network, and also commands those devices to
set up QoS guaranteed communication paths between media servers and
media clients.
The scope of this architecture is to define Web interfaces to signal
resource allocation from Web browser applications to management
servers.
4.1. Management server
Management servers are servers that control network components on the
networks. Network administrators describe network device groups and
network service description language with language called "service
definition language". Service definition language is detailed in
Section 5.1.
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Management servers serve Web APIs for clients to make resource
reservations. To trigger network resource reservations, media
clients access these Web APIs on the management servers. Upon
receiving requests from media clients, management servers calculate
appropriate communication paths between media servers and media
clients. The intermediate nodes (routers or switches) can be both of
SDN compliant and Non-SDN compliant devices, but each of those
devices have to be configurable by the management server via some
remote configuration methods such as Netconf[RFC6241] or SSH.
4.2. Media client
Media client is a client application program run on a Web browser,
which receives and present media contents to an end user. Media
client receives Media Program, which is a list of contents can be
presented, from a Program Server. When the user selects contents
from the presented list of contents, the media client starts playing
the content.
4.3. Program Server
Program Server store and provides a Media Program, which is a list of
available contents. We use HTTP to provide a Media Program to a
media client.
The content specified in the Media Program consists of the title of
the content and URL of the content. We expect content URL point to a
location of a MPEGDash [MPEGDASH] file. The Media Program can be
generated either by statically or dynamically.
At this moment, we do not define how media client finds a Program
Server. We assume this information is already available in media
client.
4.4. Media Server
Media server is a server program which store and provide metadata of
a program as a MPEGDash format, and the contents of each media
referenced from the MPEGDash formatted metadata.
Contents can be split into multiple segments by duration, or prepared
in multiple bit rates.
Since the links between Media Program, MPEGDash file and segmented
contents are described as a URL, all types of contents can store on
one media server or among multiple media servers.
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4.5. System components
+----------------+ +--------------+
|Media Client | |Program Server|
+----------------+ +--------------+
| +------------+ | | +---------+ |
| | Program +----------> | Program | |
| |Information | | | | List | |
| | Manager +--------+ | +---------+ |
| +--+---------+ | | +--------------+
| | | |
| v | | +--------------+
| +------------+ | | |Media Server |
| | Resource | | | +--------------+
| | Manager +----+ | | +----------+ |
| +--+---------+ | | +-> | Media | |
+----|------^----+ +-----> | Contents | |
| | | +----------+ |
| +-------+ +--------------+
| |
+----|--------------|--------------------+
| | | Management Server |
+----v--------------|--------------------+
| +------+ +-+-------+ |
| | Web | | Client | |
| | APIs | | Manager | |
| +------+ +---------+ |
| +---------+ ^ |
| v | |
| +----------+ +------+-----+ |
| | Topology +-->| Topology | |
| | Database | | Calculator | |
| +----------+ +------------+ |
+----------------------------------------+
Figure 2: System component
Figure 2 shows a simple component diagram of this architecture. When
a media client starts to obtain media contents from media servers,
the program information manager of the client first get the program
list from program servers. The program lists are described in the
media presentation description (MPD) format of MPEGDash. The
resource manager then access to the resource usage request Web API on
the management server. When received a request from a client, the
management server calculate the allocatable bandwidth between the
media client and the media server via the topology calculator. Then
the client manager of the management server responds a resource usage
report to the media client. Based on the information in the resource
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usage report, the media client trigger resource allocation by
accessing the resource request Web API on the management server.
Then the management server allocates bandwidth to the client via the
topology calculator and send success message back to the client.
5. API
5.1. Service definition language
Network administrators define the service specifications utilizing
the service specification language, Network Description Language
(NDL) and Service Description Language (SDL). NDL is to define the
group of network components such as router groups. With SDL,
administrators can define service specifications on the network.
Service specifications are the descriptions which define the
relationship between network devices or network groups that compose
network services. Examples of service definitions are network
configurations such as segment IP address blocks or VLAN id for the
segment. An example of NDL/SDL is shown in Figure 3 and Figure 4.
node {
ovs1;
ovs2;
media1;
media2;
pc11;
pc12;
pc13;
pc14;
pc21;
pc22;
pc23;
pc24;
}
location {
loc1 {
media1;
ovs1;
pc11;
pc12;
pc13;
pc14;
}
loc2 {
media2;
ovs2;
pc21;
pc22;
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pc23;
pc24;
}
}
group {
group101 {
media1;
media2;
pc11;
pc12;
pc13;
pc14;
pc21;
pc22;
pc23;
pc24;
ovs1;
ovs2;
}
group1623 {
ovs1;
ovs2;
}
group1624 {
ovs1;
ovs2;
}
group1625 {
ovs1;
ovs2;
}
}
link {
type = layer1;
edge1 = pc11;
edge2 = pc12;
}
Figure 3: Example of NDL
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networks {
network group101 {
address = "192.168.1.0/24";
vlan = 101;
device ovs1 {
type = L2Switch;
address = "192.168.1.1";
}
device ovs2 {
type = L2Switch;
address = "192.168.1.2";
}
device media1 {
type = Server;
address = "192.168.1.30";
}
device media2 {
type = Server;
address = "102.168.1.31";
}
}
}
Figure 4: Example of SDL
SDL also enables registrations of events on the network and event
bound actions. For example, if the traffic from certain source IP
address exceeds the defined per-flow bandwidth limitation on the
certain physical link, the traffic can be automatically shaped
according to the definitions of SDL. Administrators define resource
usage limitation using this functionality of SDL. For example,
administrators can limit the usage of bandwidth per the domain to
which user equipments attached. The bandwidth allocation for each
user is determined based on these service specifications.
5.2. Web API
5.2.1. Resource usage report
Media servers advertise resource usage of links to media servers.
The resource usage reports have two types. One is periodic resource
usage reports broadcasted from management servers. Periodic usage
reports include the uplink bandwidth usage of each server (Figure 5).
Another resource usage type is solicited usage report which is
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delivered to clients through WebAPI on the management servers. In a
solicited usage report request (Figure 6), a media client specifies
the server from which it want to download media contents. The media
server which received the solicited usage reports calculates the
physical link set which connect the client and the server, and report
available bandwidth the management server afford to allocate to the
client (Figure 7). If multiple paths between the client and the
server exist, the max available bandwidth will be returned to the
client. At a solicited resource usage report request, a media client
opens a web socket to the management server.
{
[
{
"server": <String>
"resource": {
"bandwidth": <Num> // Option
"latency": <Num> // Option
}
},
...
]
}
Figure 5: Unsolicited resource usage report json format
o server: server IP address or FQDN in string
o resource: available resource of the server
{
"from": <String>
"to": <String>
}
Figure 6: Solicited resource usage report request json format
o from: from IP address or FQDN in string
o to: to IP address or FQDN in string
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{
"resource": {
"bandwidth": <Num> // Option
"latency": <Num> // Option
}
}
Figure 7: Solicited resource usage report response json format
o resource: available resource of the server
5.2.2. Resource request
Media clients acquire reserved communication paths by accessing
resource requests API on the management server. The resource
requests have three types, initial resource request, resource
modification request from clients, and management server trigger
resource modification request. We explain these types of resource
requests in this section. According to the session_id information in
the request, the management server associate the web socket object of
the request source client and the session-id.
The clients post json format requests on the reservation. Figure 8
is the format of the resource request json.
{
"session_id": <String>
"class": <Num>
"type": <Num>
"server": <String>
"resource": {
"bandwidth": <Num> // Option
"latency": <Num> // Option
}
}
Figure 8: Resource request json format
o session_id: random created UUID to identify the session
o class: user priority class in digit number
o type: 0: Initial 1: Modification
o server: the server to which the client willing to connect
o resource: resource object contains bandwidth and latency
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5.2.2.1. Initial resource request
+------+ +------------+ +------+
|Media | | Management | |Media |
|Client| | Server | |Server|
+--+---+ +------------+ +------+
| |
| |
| | |
| RRRQ | |
+---------------> | |
| + |
| |
| RRRQR |
+--------------------------------> |
| |
| + RRRQ |
| | <--------------+
| | |
| | RRRS |
| +--------------> |
| | |
| RRRS | |
| <---------------+ |
| + |
| RRRQS |
| <--------------------------------+
| |
+ +
Figure 9: Initial resource request sequence
o RURR: Resource Usage Report Request
o RURA: Resource Usage Report Advertisement
o RRRQ: Resource Reservation ReQuest
o RRRS: Resource Reservation ReSponse
o RRRQR: Resource Reservation ReQuest Request
o RRRQS: Resource Reservation ReQuest Response
A media client initially obtains a contents list on the media server.
This contents list is described in the media presentation description
(MPD) format of MPEGDash. The acquisition of contents list is done
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by ordinal HTTP GET method. Then the client request resource usage
reports to the management server as mentioned in Section 5.2.1.
Based on information in the resource usage report and contents list,
the client determines the contents bitrate and sends a resource
request to the management server based on the determined contents
bitrate. The resource request contains a session-id randomly
generated on clients (e.g. UUID). The client simultaneously send a
resource reservation request request to media server to trigger media
server to sends a request to the management server. The RRRQR also
contains same session-id as resource request. The management server
verifies the request from the media server and the media client, and
sends response to both side if the information from the client and
the server correspond. The management server stores the session-id,
web socket information and allocated resources. This information is
used for resource modifications and keep-alive. After received RRRS
indicating the resource reservation was done successfully, the media
server send RRRQS to the media client. Then the client gets to be
able to download the media contents with guaranteed quality.
5.2.2.2. Client trigger resource modification request
A media client MAY offer resource modification requests when resource
usage reports say the uplink capacity of the media server from which
the client downloads the media contents.
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+------+ +------------+ +------+
|Media | | Management | |Media |
|Client| | Server | |Server|
+--+---+ +------------+ +------+
| |
| RRRQ + |
+---------------> | |
| + |
| |
| RRRQR |
+--------------------------------> |
| |
| + RRRQ |
| | <--------------+
| | |
| | RRRS |
| +--------------> |
| | |
| RRRS | |
| <---------------+ |
| + |
| RRRQS |
| <--------------------------------+
| |
+ +
Figure 10: Resource modification sequence (client trigger)
5.2.2.3. Management server trigger resource modification request
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+------+ +------------+ +------+
|Media | | Management | |Media |
|Client| | Server | |Server|
+--+---+ +------------+ +------+
| |
| RRMRQ + |
| <---------------+ |
| | |
| RRRQ | |
+---------------> | |
| + |
| |
| RRRQR |
+--------------------------------> |
| |
| + RRRQ |
| | <--------------+
| | |
| | RRRS |
| +--------------> |
| | |
| RRRS | |
| <---------------+ |
| + |
| RRRQS |
| <--------------------------------+
| |
+ +
Figure 11: Resource modification sequence (management server trigger)
o RRMRQ: Resource reservation modification request.
Management servers MAY trigger resource downgrade/upgrade requests to
media clients, when the used bandwidth of a certain link saturate or
become to have room. This push messaging can be done by Web sockets
or WebRTC. As resource reservation modification request contains
available resource for the received client, the client determines the
contents bitrate based on the information contained in RRMRQ and pre-
downloaded contents list information at the initial resource
reservation. The following process is similar to the initial
resource reservation described in Section 5.2.2.1.
5.2.2.4. Resource cancellation
When a client does not need the allocated resources, the client can
explicitly stop using the resource by posting a json described in
Figure 12. Upon receiving cancellation message, the management
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server disassociates session-id from the client websocket, and
release the resource bound to the session-id.
{
"session_id": <String>
}
Figure 12: Resource cancel json format
5.2.3. Keep-alive
Management servers MAY keep-alive the clients to keep monitoring the
usage of the reserved resources. While the clients can send resource
free messages explicitly at the end of media streaming, client
computers tend to disconnect from the networks suddenly or the
browser applications can be reloaded by user operations. To avoid
such kind of wasted resources, management servers send keep-alive
messages include the session-ids sent from the clients at the initial
resource reservations. When received a keep-alive message, the
client verify the session-id contained in the keep-alive message. If
the keep-alive message is not the one the client stores, the client
ignores the keep-alive messages. If the server does not receive the
keep-alive responses from the client for certain configured times,
the server free the resource bound to the session-id. By default,
the keep-alive interval is 300 seconds and the default keep-alive
timeout count is 3.
6. Security Considerations
TBD
7. IANA Considerations
TBD
8. Acknowledgement
The author would like to thank Yasuo Okabe, Osamu Nakamura and Kaoru
Maeda for their good contributions to this document.
9. References
9.1. Normative References
[RFC6455] Fette, I. and A. Melnikov, "The WebSocket Protocol",
RFC 6455, December 2011.
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9.2. Informative References
[MPEGDASH]
"ISO/IEC 23009-1:2014: Dynamic adaptive streaming over
HTTP (DASH) -- Part 1: Media presentation description and
segment formats", May 2014,
<http://standards.iso.org/ittf/PubliclyAvailableStandards/
index.html>.
[RFC6241] Enns, R., Bjorklund, M., Schoenwaelder, J., and A.
Bierman, "Network Configuration Protocol (NETCONF)",
RFC 6241, June 2011.
Authors' Addresses
Yoshiharu Tsuzaki
Kyoto University
Email: tsuzakiyo@net.ist.i.kyoto-u.ac.jp
Ray Atarashi
IIJ Innovation Institute Inc.
Email: ray@iijlab.net
Shigeya Suzuki
Keio University
Email: shigeya@wide.ad.jp
Koshiro Mitsuya
Lepidum Co. Ltd.
Email: mitsuya@lepidum.co.jp
Kouji Okada
Lepidum Co. Ltd.
Email: okd@lepidum.co.jp
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