Software-defined networks (SDN) may be the future of telecom and enterprise networks, but according to analysts at research firm IDC, vendors are trying to implement SDN in a way that’s holding up that future.
Cisco Systems, for example, has staked out a position that virtualized networks should be built into the hardware of the network infrastructure itself. Meanwhile, many virtualization and other networking vendors are taking different approaches.
High-end networking vendor Huawei announced this week that it agrees with Cisco’s position—to a point. Rather than rely on virtualization capabilities built into Cisco’s switches, Huawei built the ability into its own switches, with the help of Microsoft.
Huawei announced this week that it had implemented the Windows Server 2012 Hyper V Network Virtualization function into its own CE12800 datacenter switches. The combination is designed to allow the company’s high-performance, high-cost switches to act as a gateway that connects physical networks to virtualized, often multitenant networks on cloud platforms or elsewhere, according to the company.
The Huawei CE 12800 series is Huawei’s Cloud Engine brand, which is designed to provide as much at 64T bit/sec of throughput at Layers 2 and Layer 3 to provide connections among datacenters, between campus networks or other links between networks with high volume and resource demands. The largest of the CE line, the CE12816 that was introduced in May, has connections for as many as 192 100Gbit/sec Ethernet connections, 384 40Gbit/sec connections of 1,536 10Gbit/sec ports, a range Huawei suggested is designed to allow the switches to support networks running several generations of switch, or connect both large and small network infrastructures through the same switching platform.
The CE switches are already designed to smoothly connect physical networks to virtual by merging many virtual switches into a single physical switch. CE switches are also designed to support large-scale layer 2 networks of up to 500 nodes, using Transparent Interconnection of Lots of Links (TRILL), the IEEE-certified standard protocol to flexibly connect many network links without making each link static. TRILL gateways are also referred to as Routing Bridges (RBridges), as described in the IEEE spec.
Virtual LANs make connections to traditional networks difficult because they use a specific VLAN ID in the Ethernet frame headers, but not all VLANs use different IDs. Instead they require Ethernet switches to separate VLANs with identical IDs to avoid confusion if traffic meant for one should accidentally hit another. VLANs also function only within a single IP subnet, limiting the number of network or cloud nodes to which VMs can migrate, according to Microsoft.
The Virtual IP addresses used by VLANs are also tied to the physical hardware of their network of origination. To move through a gateway to a different network segment or into the cloud, each VM or VLAN would have to change every IP number it uses to one that matches the target environment, or allow managers to reconfigure the whole VLAN to accommodate the new environment.
Windows Hyper-V Network Virtualization acts as a de facto network platform, managing the IP addresses of VMs and devices on a virtual network and resolving overlaps in IP addresses when VMs or VLANs move or extend from network segments with one Hyper-V Network Virtualization server to a segment with another server. The Hyper-V Network machines exchange, consolidate and reconfigure addresses automatically during the migration.
That makes migration of Hyper-V-based virtual machines simpler between local-network segments, something that can be overwhelmed by the size of the challenge of resolving, changing or integrating potentially thousands of overlapping IP addresses when connecting one large virtualized environment to another.
Huawei, by running Microsoft’s Hyper-V Network Virtualization software on the switch itself, rather than a physical server that isn’t optimized for high-volume networking, puts right into the switch the ability to resolve IP addresses and network configurations between two or more environments using Hyper-V-based virtual machines and virtual LANs.
Ideally, that resolution should be done at Layer 2—below the Layer 3 addressing information—resulting in less need to resolve so large a number of IP addresses, according to Huawei documentation. Huawei’s switch supports connections at Layer 2, but can also act as a gateway at Layer 3. With Hyper-V Network Virtualization, it can do so smoothly with Windows-based virtual machines or with Microsoft-based clouds such as the public Azure or internal Hyper-V-based cloud platforms.
Huawei also supports SDN connectivity requirements from Internet providers such as the Chinese Tencent and Alibaba and will continue to add more multipoint, multi-tenant SDN connectivity options as they are developed, the company said.