The Next Evolution of Enterprise Connectivity
By Amit Srivastava, Sr. Director, Fabric Product Management
When the XEROX corporation introduced Ethernet as a means of connectivity and communication in the 70’s, the idea was revolutionary for that time. Computer systems could use a shared medium for connectivity and communication. As with all good ideas, headwinds meant evolution and with Ethernet, evolution happened quickly. Engineers soon realized that a single broadcast medium wasn’t scalable and that dedicated broadcast zones within the same physical media were needed to accommodate growth.
Since then, we’ve come a long way. The endpoints have changed, the service requirements have changed, and the media to reach our endpoints have changed. However, citing this early phase matters because, even today, the fundamental issue hasn’t changed — we need connectivity and our own broadcast domain to reach an endpoint.
To achieve high performance and low latency, we want a private highway. Today, we call that private highway a VLAN (aptly called ‘virtual local area network), and it’s a fundamental networking concept designed with just one thing in mind – to create separate broadcast domains over a shared access media!
With VLANs solving a lot of connectivity problems, it quickly became the most cost-effective and scalable technology to achieve network segregation and technology delivery mechanisms. Enterprises started looking for mechanisms to extend their broadcast domains across different geographical locations. Researchers and innovators started addressing the problem.
- During the late 90s, tech bellwether Cisco introduced the concept of tag switching over IP networks. Tag switching was submitted to IETF for standardization and evolved to present-day MPLS (multiprotocol label switching). This introduced a way to label and send packets over an IP network, and applications created with MPLS soon became very popular.
- Label stacking enabled broadcast domain extensions across geographies. Label Distribution Protocol (LDP) and later BGP (Border Gateway Protocol) extensions were created to distribute labels and enable services like L3VPN (Layer 3 VPNs) and EoMPLS (Ethernet Over MPLS).
- EoMPLS (through IETF’s Martini draft) created a mechanism to send layer 2 frames over an MPLS network creating point-to-point network connections that extended an enterprise’s broadcast domain over geographies. This became the standard for interconnecting enterprise locations.
- However, as a point-to-point connection, it had its limitations and soon there was a need to have multipoint connections. VPLS (Virtual Private LAN Service) emerged, which is an Ethernet-based multipoint-to-multipoint service enabling enterprises to extend their LAN over to the provider network which then ‘switches’ connections over its MPLS core to create a distributed switch for enterprises. This is a very desirable feature for enterprises who want to ‘emulate’ a LAN with edges distributed across geographies.
Although VPLS works great as an Ethernet-based L2-VPN service, it does run into some scale issues with a very large number of locations/mac-address. If you use it within its scale limits it’s a technology that is easy to deploy and understand, and it’s still a popular technology that helps solve enterprise connectivity problems.
However, with the rise of the data center as the center of the universe for enterprise networks, VPLS did run into scale limitations for MAC addresses. This gave way to a ‘hybrid’ l2/l3 overlay VPN technology – VxLAN with EVPN (VxLAN being the IP in MAC encapsulation technology and EVPN a BGP AF extension designed to provide control-plane to VxLAN). Together they solve the scale, resiliency, and endpoint mobility issues that were not addressed by VPLS.
Having said that, VPLS and EoMPLS are still very widely deployed technologies that provide low latency, fast and cost-effective L2 VPN connections.
Summarizing our history lesson here, we have evolved from Ethernet to carving out broadcast domains within shared media using VLANs to extending VLANs over geographies using EoMPLS, VPLS, and now most recently EVPN with VxLAN.
Having said all this, evolution never stops, and we’re evolving into a new world that will require new thinking to accommodate widely distributed IT.
- Datacenter infrastructures are changing. The data center, of late, was the center of the enterprise network with the bulk of compute and storage sitting there. However, with the increased use of public clouds and other distributed compute infrastructure, organizations are finding that their networks need to accommodate new forms of connectivity.
- Now throw in 5G into the mix and you will find that compute now is moving closer to the place it’s being used. Micro data centers are compute locations emerging close to the network edges (also called Edge datacenters) to enable low latency access to data processing and storage. Instead of a few large data centers and a couple of public clouds, organizations are evolving toward dozens, hundreds, or even thousands of distributed loci/nodes for data center compute, storage, and connectivity.
- With more remote end-users and a distributed workforce, users need to access their enterprise applications securely and in compliance with policies without being hair pinned to a data center location.
- Enterprises can’t function with datacenters being the only locations enforcing enterprise policies.
We’re seeing these new demands driving a shift in security technologies. Enterprises are now redesigning their networks with a zero-trust approach across all devices, everywhere. Garter came up with reference architecture SASE (Secure Access Service Edge) that includes SWG, CASB, FwaaS, and SD-WAN to enable organizations to address today’s most pressing security concerns with remote access and a non-existent perimeter.
Now if we take a step back and look back at our network evolution and the present-day dynamics, there is one common requirement that is a constant – it’s the need for ‘connectivity’.
Applications and technologies have evolved and with that our need for better, faster, and more reliable connectivity. With IoT devices at the edge rising exponentially, the need for better infrastructure and connectivity has become more apparent. The word G (generation) in the cellular technology world gets prefixed by a new number approximately every 10 years.
- 1G in the late seventies/early 80s was marked by the rise of analog telecommunication devices.
- Next came 2G around the early 90s with cell phone technology and the ability to send things like ’text messages’ over phones.
- 3G was next around the late 90s and 2000s with cellphones getting Internet connections.
- 4G around the late 2000s was the time when mobile Internet truly took off.
With 5G however, we are not just talking about another spectrum. To accommodate a multitude of IoT devices and the need for better, faster, and more reliable Internet, new infrastructure and connectivity are required. Like I’ve mentioned earlier, this new ‘generation’ means having compute (and decision-making abilities, like policy application) with the entire network security apparatus) closer to the data source and in places where we would not imagine putting critical infrastructure 10 years ago. Connectivity in this new world will be critical, and not every connectivity provider and carrier measures up with the last mile capacity needed for the upcoming evolution toward massively distributed infrastructure.
Zayo leads the pack of operators in its ability to solve connectivity problems using Ethernet connectivity solutions like EPL (Ethernet Private Line), EVPL (Ethernet Virtual Private LAN) using EoMPLS, and ELAN (Ethernet LAN) using VPLS to name a few. With a last mile reach parallel to none, 31 locations across North America and Western Europe that boast 400G long haul infrastructure routes, accelerating deployment of 800G service in North America, multiple cloud-onramp locations to public clouds (like AWS, Azure, Google, etc.) and value-added services like DIA (direct internet access), DDoS mitigation, and managed SDWAN, Zayo can solve your enterprise connectivity problems and make sure your network is ahead of the game as we find ourself at the cusp of another network evolution.