软件定义网络OpenFlow交换机规范 V1.0.0

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"OpenFlow技术详解" OpenFlow是软件定义网络（Software Defined Network，SDN）中的一个关键技术，旨在提供一个统一的网络控制协议，以便更好地管理和控制网络。下面是OpenFlow技术的详细介绍： **什么是OpenFlow？** OpenFlow是一种开放的网络控制协议，允许网络管理员通过远程控制器来管理和控制网络设备。OpenFlow协议定义了一个通用的接口，使得不同的网络设备和控制器可以互相通信，从而实现了网络的统一管理和控制。 **OpenFlow Switch** OpenFlow Switch是一个网络设备，它可以与远程控制器通信，接收控制命令和配置信息。OpenFlow Switch由多个组件组成，包括流表、组件表、_meter 表和计数器表等。这些组件共同实现了网络流量的控制和管理。 **OpenFlow协议** OpenFlow协议是一种基于 TCP 的协议，用于在OpenFlow Switch和远程控制器之间进行通信。OpenFlow协议定义了多种消息类型，包括控制消息、配置消息和状态消息等。这些消息类型使得OpenFlow Switch可以接收控制命令、配置信息和状态信息，从而实现了网络的统一管理和控制。 **OpenFlow Switch的组件** OpenFlow Switch由多个组件组成，包括： * 流表（Flow Table）：用于存储网络流量的规则和动作。 * 组件表（Group Table）：用于存储网络组件的信息。 * _meter 表（Meter Table）：用于存储网络流量的计量信息。 * 计数器表（Counter Table）：用于存储网络流量的计数信息。这些组件共同实现了网络流量的控制和管理。 **OpenFlow的应用** OpenFlow技术有广泛的应用前景，包括： * SDN网络：OpenFlow是SDN网络的核心技术之一，用于实现网络的统一管理和控制。 * 网络虚拟化：OpenFlow可以用于实现网络虚拟化，提供更好的网络资源利用率和灵活性。 * 云计算：OpenFlow可以用于实现云计算中的网络管理和控制。 **OpenFlow的优势** OpenFlow技术有多种优势，包括： * 统一的网络管理：OpenFlow提供了一个统一的网络管理接口，易于管理员管理和控制网络。 * 灵活的网络配置：OpenFlow允许管理员灵活地配置网络设备和控制器，实现了网络的高效管理。 * 高性能的网络控制：OpenFlow提供了高性能的网络控制，能够实时地监控和控制网络流量。 OpenFlow技术是SDN网络中的一个关键技术，提供了一个统一的网络控制协议，能够实现网络的统一管理和控制。OpenFlow技术有广泛的应用前景，包括SDN网络、网络虚拟化和云计算等领域。

OpenFlow Switch Speciﬁcation Version 1.0.0

3.4 Matching

Match table

Parse header

ﬁelds

(see below)

Optional

802.1d STP

processing

Match table

Send to

controller via

Secure Channel

Apply actions

yes

Packet in from

network

Figure 2: Packet ﬂow in an OpenFlow switch. As discussed in Section 4.5,

support for 802.1D is optional.

Set VLAN ID and

PCP. Use

encapsulated Eth

type for next Eth

type check

Eth type =

0x8100?

Initialize Headers

Set input port,

Ethernet source,

destination, and type;

set all others to zero

Eth type =

0x0800?

Not IP

Fragment?

Set IP source,

destination,

protocol, and

ToS ﬁelds

Use UDP/TCP

source and

destination for

L4 ﬁelds

IP Proto =

6 or 7?

IP Proto =

Use ICMP

type and code

for L4 ﬁelds

Packet Lookup

Use assigned

header ﬁelds

decision

yes

Eth type =

0x0806?

Set IP source,

destination from

within ARP

packet

Figure 3: Flowchart showing how header ﬁelds are parsed for matching.

On receipt of a packet, an OpenFlow Switch performs the functions shown

in Figure 2. Header ﬁelds used for the table lookup depend on the packet type

as described below (and shown in Figure 3).

• Rules specifying an ingress port are matched against the physical port

that received the packet.

• The Ethernet headers as speciﬁed in Table 2 are used for all packets.

OpenFlow Switch Speciﬁcation Version 1.0.0

• If the packet is a VLAN (Ethernet type 0x8100), the VLAN ID and PCP

ﬁelds are used in the lookup.

• (Optional) For ARP packets (Ethernet type equal to 0x0806), the lookup

ﬁelds may also include the contained IP source and destination ﬁelds.

• For IP packets (Ethernet type equal to 0x0800), the lookup ﬁelds also

include those in the IP header.

• For IP packets that are TCP or UDP (IP protocol is equal to 6 or 17),

the lookup includes the transport ports.

• For IP packets that are ICMP (IP prototcol is equal to 1), the lookup

includes the Type and Code ﬁelds.

• For IP packets with nonzero fragment oﬀset or More Fragments bit set,

the transport ports are set to zero for the lookup.

A packet matches a ﬂow table entry if the values in the header ﬁelds used for

the lookup (as deﬁned above) match those deﬁned in the ﬂow table. If a ﬂow

table ﬁeld has a value of ANY, it matches all possible values in the header.

To handle the various Ethernet framing types, matching the Ethernet type is

handled in a slightly diﬀerent manner. If the packet is an Ethernet II frame, the

Ethernet type is handled in the expected way. If the packet is an 802.3 frame

with a SNAP header and Organizationally Unique Identiﬁer (OUI) of 0x000000,

the SNAP protocol id is matched against the ﬂows Ethernet type. A ﬂow entry

that speciﬁes an Ethernet type of 0x05FF, matches all Ethernet 802.2 frames

without a SNAP header and those with SNAP headers that do not have an OUI

of 0x000000.

Packets are matched against ﬂow entries based on prioritization. An entry that

speciﬁes an exact match (i.e., it has no wildcards) is always the highest priority.

All wildcard entries have a priority associated with them. Higher priority entries

must match before lower priority ones. If multiple entries have the same priority,

the switch is free to choose any ordering. Higher numbers have higher priorities.

For each packet that matches a ﬂow entry, the associated counters for that

entry are updated. If no matching entry can be found for a packet, the packet

is sent to the controller over the secure channel.

4 Secure Channel

The secure channel is the interface that connects each OpenFlow switch to a

controller. Through this interface, the controller conﬁgures and manages the

switch, receives events from the switch, and send packets out the switch.

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软件定义网络OpenFlow交换机规范 V1.0.0

NX10_Open_CS_Wizard1_NXOPENC#_nxopen_

Open_CV_Optical_Flow_2：Open_CV_Optical_Flow_2

open_sdk_r5923_lite.jar

定义了一个函数体open_file():，ctrl.open_file = open_file()和ctrl.open_file = open_file有什么区别

open_set, closed_set = dict(), dict() # key - value: hash表 open_set[self.calc_grid_index(nstart)] = nstart while 1: if len(open_set) == 0: print("Open_set is empty...") break

if not self.verify_node(node): continue if n_id in closed_set: continue if n_id not in open_set: open_set[n_id] = node # 直接加入a new node else: if open_set[n_id].cost > node.cost: open_set[n_id] = node

bool Form::slotOpenRed() { open_red=true; return open_red; } bool Form::slotCloseRed() { open_red=false; return open_red; }

c_id = min(open_set, key=lambda o: open_set[o].cost + self.calc_heuristic(ngoal, open_set[o]))

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