RYU Learning Guide

1. RYU 学习指南
State Key Laboratory of Networking and Switching Technology
Future Networking Laboratory
Cheng Li

2. Agenda
What is RYU
How RYU workHow to develop
What RYU can do

3. What is RYU
Ryu is a component-based software defined networking framework.

4. What is RYU
OSS SDN Framework founded by NTT:
•Python library for SDN
•Apache v2 license
•Supports various protocols for managing network devices:
- OpenFlow, Netconf, OF-config, SNMP etc.
Features:
•OpenFlow
- Version:1.0,1.2,1.3,1.4,1.5
•Parsing and building various protocols packets:
- IP, UDP,TCP,MPLS…
•Ryu can configure Open vSwitch directly without ovs-vsctl, ovsdb-client
•Integration with other project
- OpenStack
- HA with Zookeeper
- IDS(Intrusion Detection System) with snort

5. What RYU can do
• Various SDN Application and library:
- simple_switch firewall router…
- LACP,STP…
- RESTAPI, RPC
• Integration with other project:
- OpenStack
- HA with Zookeeper
- IDS(Intrusion Detection System) with snort
• Topology Viewer
- Topology discovery
- Flow entry management.

6. User
RYU 在工业界得到了不错的
应用，使用 RYU 作为控制器
的厂家包括 pica8, centec ，
broadcom 等。开源软件交换
机 OVS,CPQD 等也均支持
RYU 控制器。更多企业的
SDN 解决方案采用 RYU 控制
器。
RYU 以其轻巧，快速开发，
协议支持完整，支持和其他开
源软件协同工作的特点，在开
源控制器的竞争中获得了一席
之地。
Ref:
http://www.slideshare.net/apnic/ryu-sdn-framework?qid=b548fb40-1f9d-477c-ad35-2b9

7. How to develop
• Installation
• Getting started
• CLI
• GUI
• RESTAPI
• Simple_switch

8. Installation
• Pip install
~pip install ryu
• Native Installation form Source
~git clone https://github.com/osrg/ryu.git
~cd ryu
~sudo python setup.py install
• Installhelper
~git clone https://github.com/sdnds-tw/ryuInstallHelper.git
~cd ryuInstallHelper
~./ryuInstallHelper.sh

9. Getting Started
Startup Options
●ryu-manager 启动 ryu, 如果不加任何参数，则默认启动 ofphandler 模块。
●ryu run 等同于 ryu-manager
●Ryu-manager –h 查看帮助信息
●--verbose 打印详细信息
●--version
●--observe-links 自动下发 LLDP ，用于拓扑发现。
●…
●Example: ryu-manager simple_switch.py ofctl_rest.py –observe-links

10. CLI
CLI register
●参数注册统一使用 oslo ： OpenStack Common Libraries 。
●cfg.py: CONF=oslo.config.cfg.ConfigOpts()
●from ryu import cfg :cfg 模块定义了 CONF 对象
●CONF.register_cli_opts(
[cfg.StrOpt(“wsapi-port”, default =8080, help = ‘webapp listen port’ )])

11. GUI
● 使用官方 GUI
o 官方提供 GUI 套件
o 详细教程：
http://www.muzixing.com/pages/2015/04/21/ryu316-guian-zhuang-yu-topologymo-kuai-fen-x
● 使用第三方 GUI
o 第三方 GUI 提供者有很多
o http://sdnhub.org/releases/sdn-starter-kit-ryu/
o ANT GUI

12. GUI

13. GUI

14. GUI

15. RESAT API
RYU 提供了 RESTAPI ， 用于可以使用 RESTAPI 来开发应用程序。
•Ofctl_rest.py 提供 OpenFlow 方面的 REST API 接口：
get the list of all switches GET /stats/switches
get the desc stats of the switch GET /stats/desc/<dpid>
get flows stats of the switch GET /stats/flow/<dpid>
get flows stats of the switch filtered by the fields ： POST /stats/flow/<dpid>
•Rest_topology.py 提供获取拓扑相关 API:
get all the switches GET /v1.0/topology/switches
get the switch GET /v1.0/topology/switches/<dpid>
get all the links GET /v1.0/topology/links
get the links of a switch GET /v1.0/topology/links/<dpid>

16. Write your first APP
http://ryu.readthedocs.org/en/latest/writing_ryu_app.html

17. Program model

18. Simple hub

19. Simple hub
Controller
SwitchHost A Host C
Host B
Packet Packet
Packet
Packet IN
Packet out

20. Simple hub
控制器需要做的事情：
•创建一个 app 类，用于描述 hub 的行为：
•注册监听 Packet_in 事件的处理函数，用于处理 packet_in 事件

21. Event
EventOFPMsgBase
Eventbase

22. OFPEVENT
Event
MSG(datapath, version,msg_type, msg_len, xid, buf)
Datapath
ProtocolDesc
(ofproto, ofproto_parser)
Others

23. OFPActionOutput
OFPActionOutput
OFPAction
OFPActionHeader
StringifyMixin

24. Simple switch
控制器需要做的事情：
•创建一个 app 类，用于描述 switch 的行为：
•注册监听 Packet_in 事件的处理函数，用于处理 packet_in 事件：相比 hub ，多了 MAC 地址自学习功
能
•链接： http://osrg.github.io/ryu-book/en/html/switching_hub.html

25. Parsing Packet

26. Building Packet

27. Traffic Monitor
控制器需要做的事情：
•创建一个 app 类，用于描述流量监控，继承 Simple switch ；
•完成发送获取网络信息报文的函数；
•注册处理统计数据回复报文的 handler 。
•教程：
•http://osrg.github.io/ryu-book/en/html/traffic_monitor.html
•http://www.muzixing.com/pages/2015/03/04/traffic-monitor-in-ryu.html
Controller
Switch
Stats_reqeust Stats_reply

28. How RYU work
• Architecture
• RYU code
• Call Graph

29. Architecture

30. RYU code

31. Call Graph

32. Data plane
Main(RYU)
AppManager
Service brick (event router)
OpenVSwitch
OFHandler(RyuAPP)
ofprotoofproto_v1_* ofproto_v1_*_parser
OpenFlowController
Hello
handler
Switch features
handler
Handlers…
libARP ipv4… icmp
Datapaths
dp1 dp2 dp3 dpn
StreamServer
OpenVSwitch
OpenVSwitch
Socket Client
Read&wirte socket
Socket server
connect
CONF
APPn APP2 OFPHandlerAPP list
event
event
event
response
New datapath

34. Thank you
MUZIXING.COM
State Key Laboratory of Networking and Switching Technology
Future Networking Laboratory
Cheng Li