2.?SONIC

有了 SAI, 這讓網(wǎng)絡(luò)操作系統(tǒng)不再關(guān)心底層怎么與專有硬件通信，操作系統(tǒng)廠商可以專注于網(wǎng)絡(luò)操作系統(tǒng)的開(kāi)發(fā)，其中以 SONIC 最為突出，他是 Microsoft/Azure 網(wǎng)絡(luò)操作系統(tǒng)，由微軟和多家廠商一起開(kāi)發(fā)，并且開(kāi)源。

2.1.?什么是SONIC?

SONiC 是一個(gè)基于 Linux 的開(kāi)源網(wǎng)絡(luò)操作系統(tǒng)，運(yùn)行在多個(gè)供應(yīng)商和 ASICs 的交換機(jī)上。SONiC 提供一整套網(wǎng)絡(luò)功能，如 BGP 和 RDMA，這些功能在一些最大的云服務(wù)提供商的數(shù)據(jù)中心經(jīng)過(guò)生產(chǎn)驗(yàn)證。它為團(tuán)隊(duì)提供了創(chuàng)建所需網(wǎng)絡(luò)解決方案的靈活性，同時(shí)利用大型生態(tài)系統(tǒng)和社區(qū)的集體力量。

2.2.?SONIC 系統(tǒng)架構(gòu)^[13]

SONIC 系統(tǒng)的體系結(jié)構(gòu)由各種模塊組成，這些模塊通過(guò)一個(gè)集中的、可伸縮的基礎(chǔ)設(shè)施彼此交互。這個(gè)基礎(chǔ)結(jié)構(gòu)依賴于 redis-database 引擎的使用: 鍵值數(shù)據(jù)庫(kù)提供獨(dú)立于語(yǔ)言的接口、數(shù)據(jù)持久性、復(fù)制和所有聲音子系統(tǒng)之間的多進(jìn)程通信的方法。

SONIC 通過(guò)依賴 redis-engine 基礎(chǔ)結(jié)構(gòu)提供的發(fā)布者/訂閱者消息傳遞范式，應(yīng)用程序可以只訂閱它們所需的數(shù)據(jù)視圖，并避免與其功能無(wú)關(guān)的實(shí)現(xiàn)細(xì)節(jié)。

SONIC 將每個(gè)模塊放在獨(dú)立的docker容器中，以保持語(yǔ)義仿射組件之間的高內(nèi)聚性，同時(shí)減少脫節(jié)組件之間的耦合。每個(gè)組件都被編寫為完全獨(dú)立于平臺(tái)特定的細(xì)節(jié)，而這些細(xì)節(jié)是與低層抽象交互所必需的。

SONIC 將其主要功能組件分解為以下 docker 容器：

• Dhcp-relay
• Pmon
• Snmp
• Lldp
• Bgp
• Teamd
• Database
• Swss
• Syncd

2.3.?SONIC 的功能發(fā)展

我們來(lái)看一下 SONIC 的功能發(fā)展 (來(lái)源于 SONIC 官網(wǎng)) ^[14]

Release	Release Date	SAI version	Features Included
SONiC.201705	5/15/2017	0.9.4	BGP
			ECMP
			LAG
			LLDP
			QoS – ECN
			QoS – RDMA
			Priority Flow Control
			WRED
			COS
			SNMP
			Syslog
			Sysdump
			NTP
			COPP
			DHCP Relay Agent
			SONiC to SONiC upgrade
			Multiple Images support
			One Image
SONiC.201709	9/15/2017	0.9.4	VLAN
			ACL permit/deny
			IPv6
			Tunnel Decap
			Mirroring
			Post Speed Setting
			BGP Graceful restart helper
			BGP MP
SONiC.201712	12/15/2017	1	Fast Reload
			SONiC Support SAI 1.0
			TACACS+
			LACP Fallback
			MTU Setting
			Vlan Trunk
			Static Port breakout1
			Dynamic ACL Upgrade
			SWSS Unit Test Framework
			CobfigDB framework
SONiC.201803	3/15/2018	1.2
			Critical Resource Monitoring
			MAC Aging
			IPv6 ACL
			BGP/Neighbor-down fib-accelerate
			PFC WD
SONiC.201807	7/30/2018	1.3
			gRPC
			Dtel support
			SONiC Architecture and User Manual (Documentation)
			Sensor transceiver monitoring
			LLDP extended MIB: lldpremtable, lldplocporttable, lldpremmanaddrtable, lldplocmanaddrtable, lldplocporttable, lldpLocalSystemData
SONiC.201811	11/30/2018	1.3	Release Note
			Debian Kernel Upgrade to 4.9
			Warm Reboot
			Incremental Config (IP, LAG, Port shut/unshut)
			Asymmetric PFC
			PFC Watermark
			Routing Stack Graceful Restart
			Basic VRF and L3 VXLAN
SONiC.201904	4/30/2019	1.4	Release Note
			FRR as default routing stack
			Upgrade each docker to stretch version
			Upgrade docker engine to 18.09
			Everflow enhancement
			Egress ACL bug fix and ACL CLI enhancement
			L3 RIF counter support
			PMon Refactoring
			BGP-EVPN support(type 5), (related HLD?Fpmsyncd,Vxlanmgr,template)
			Transceiver parameter tuning?PR pending on CR sign off
SONiC.201910	10/30/2019	1.5	Progress Tracking
			ZTP – design review in progress
			BFD – SW – 100ms interval from FRR
			NAT
			STP/PVST
			Mgmt VRF
			Multi-DB optimization
			Test to Pytest
			sFlow
			Management Framework (Tentative )
			Platform Driver Development Framework
			Build Improvements
			Error handling enhancements
			L2 functional and performance enhancements
			L3 perf enhancement
			BroadView BST
			VRF
			Configuration Validation
			Dynamic Break Out
			Platform APIs move to new APIs *
			Sub-port support
Backlog
			CLI framework
			VRF (Taken)
			L3 MLAG (Taken)
			EVPN
			RDMA CLI enhancement
			Virtual path for streaming telemetry (pushed off)
			Management VRF (pushed off)
			Port and Vlan configuration and validation (TBD)

3. 結(jié)束語(yǔ)

今天我們先聊這些，我們大致了解一下開(kāi)放型網(wǎng)絡(luò)包含的幾個(gè)重要組件，開(kāi)源軟件的概念，開(kāi)源的網(wǎng)絡(luò)操作系統(tǒng)的概念，開(kāi)放的計(jì)算硬件有何而來(lái)，軟件定義網(wǎng)絡(luò)的概念，但是開(kāi)放型網(wǎng)絡(luò)中還包含以下組件：

• 網(wǎng)絡(luò)功能虛擬化
• 云計(jì)算
• 自動(dòng)化
• 敏捷型開(kāi)發(fā)方法和處理過(guò)程

SONIC 作為網(wǎng)絡(luò)操作系統(tǒng)在其中扮演很重要的角色，如果想進(jìn)一步了解 SONIC 子系統(tǒng)的各個(gè)功能以及邏輯，網(wǎng)絡(luò)功能虛擬化，云計(jì)算，網(wǎng)絡(luò)自動(dòng)化，以及敏捷型開(kāi)發(fā)方法和處理過(guò)程，請(qǐng)關(guān)注我們。

參考文獻(xiàn)：
[1]?https://en.wikipedia.org/wiki/Software-defined_networking
[2]?https://en.wikipedia.org/wiki/Open_source
[3]?https://en.wikipedia.org/wiki/Open-source_software
[4]?https://www.opencompute.org/about
[5]?https://aptira.com/what-is-open-networking/
[6]?https://events19.linuxfoundation.org/wp-content/uploads/2017/11/Open-Hardware-and-Open-Networking-Software-How-We-Got-Here-and-Where-We-are-Going-Steven-Noble-Big-Switch-Networks-_-NetDEF.pdf
[7]?https://www.opencompute.org/wiki/Networking/ONIE
[8]?https://www.openswitch.net/about/
[9]?http://opennetlinux.org/
[10]?https://events19.linuxfoundation.org/wp-content/uploads/2017/11/Open-Hardware-and-Open-Networking-Software-How-We-Got-Here-and-Where-We-are-Going-Steven-Noble-Big-Switch-Networks-_-NetDEF.pdf
[11]?https://events19.linuxfoundation.org/wp-content/uploads/2017/11/Open-Hardware-and-Open-Networking-Software-How-We-Got-Here-and-Where-We-are-Going-Steven-Noble-Big-Switch-Networks-_-NetDEF.pdf
[12]?https://www.opencompute.org/documents/switch-abstraction-interface
[13]?https://github.com/Azure/SONiC/wiki/Architecture
[14]?https://github.com/Azure/SONiC/wiki/Sonic-Roadmap-Planning