藍云-21V-Blue-Cloud-Logo-600x172.png){kind=logo}
藍云-21V-Blue-Cloud-Logo-反白-600x172.png){kind=logo}
2.?SONIC
有了 SAI, 這讓網(wǎng)絡操作系統(tǒng)不再關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)絡操作系統(tǒng)的開發(fā)，其中以 SONIC 最為突出，他是 Microsoft/Azure 網(wǎng)絡操作系統(tǒng)，由微軟和多家廠商一起開發(fā)，并且開源。
2.1.?什么是SONIC?
SONiC 是一個基于 Linux 的開源網(wǎng)絡操作系統(tǒng)，運行在多個供應商和 ASICs 的交換機上。SONiC 提供一整套網(wǎng)絡功能，如 BGP 和 RDMA，這些功能在一些最大的云服務提供商的數(shù)據(jù)中心經過生產驗證。它為團隊提供了創(chuàng)建所需網(wǎng)絡解決方案的靈活性，同時利用大型生態(tài)系統(tǒng)和社區(qū)的集體力量。
2.2.?SONIC 系統(tǒng)架構[13]
SONIC 系統(tǒng)的體系結構由各種模塊組成，這些模塊通過一個集中的、可伸縮的基礎設施彼此交互。這個基礎結構依賴于 redis-database 引擎的使用: 鍵值數(shù)據(jù)庫提供獨立于語言的接口、數(shù)據(jù)持久性、復制和所有聲音子系統(tǒng)之間的多進程通信的方法。
SONIC 通過依賴 redis-engine 基礎結構提供的發(fā)布者/訂閱者消息傳遞范式，應用程序可以只訂閱它們所需的數(shù)據(jù)視圖，并避免與其功能無關的實現(xiàn)細節(jié)。
SONIC 將每個模塊放在獨立的docker容器中，以保持語義仿射組件之間的高內聚性，同時減少脫節(jié)組件之間的耦合。每個組件都被編寫為完全獨立于平臺特定的細節(jié)，而這些細節(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
我們來看一下 SONIC 的功能發(fā)展 (來源于 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. 結束語
今天我們先聊這些，我們大致了解一下開放型網(wǎng)絡包含的幾個重要組件，開源軟件的概念，開源的網(wǎng)絡操作系統(tǒng)的概念，開放的計算硬件有何而來，軟件定義網(wǎng)絡的概念，但是開放型網(wǎng)絡中還包含以下組件：
- 網(wǎng)絡功能虛擬化
- 云計算
- 自動化
- 敏捷型開發(fā)方法和處理過程
SONIC 作為網(wǎng)絡操作系統(tǒng)在其中扮演很重要的角色，如果想進一步了解 SONIC 子系統(tǒng)的各個功能以及邏輯，網(wǎng)絡功能虛擬化，云計算，網(wǎng)絡自動化，以及敏捷型開發(fā)方法和處理過程，請關注我們。
參考文獻：
[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