11-Apr-2016

Shortest-path-bridging is increasingly expanding its reach beyond the data center and is providing network administrators a new alternative for service separation, while at the same time reducing or eliminating the use of spanning tree in their networks.

What is shortest-path-bridging?

Shortest path bridging is an open standard supported by multiple vendors and is fully described in IEEE 802.1aq. in essence, it uses MAC-in-MAC encapsulation in the data plane and IS-IS in the control plane to provide loop-free separation between services in a network.

Tags - Software Defined Networking

spb farewell spanning tree
Browse Blog Posts
Browse Blog Authors

What’s the traditional way to deploy network services?

The traditional approach to deploying services in a network is to declare a VLAN for each individual service. For instance, a business might declare a VLAN for Voice, a VLAN for their financial database, a VLAN for their video surveillance cameras, and so on.

SPB farewell spanning tree

Each location needing access to a service is gets the VLAN for that service delivered there.

What are the problems with this approach?

Problem one is complexity. As the number of services and the number of locations grows, things get increasingly difficult to manage. Each new location, each new service, each departmental move causes a big change in the network since the VLANs have to be added to or modified at every switch in the path. This is time consuming and prone to error, and the problem gets worse the bigger our network gets. In the diagram below, adding CMS as a service means performing configurations on 5 different switches.

SPB farewell spanning tree

The second problem is a side-effect of using VLANs. VLANs are layer 2 constructs, and the way to learn a layer 2 topology is through the use of spanning tree. In order to avoid loops, spanning tree will leave physical links unused. That gigabit link you paid dearly to provision may in fact be sitting idle.

SPB farewell spanning tree

 

What’s more, a given service may not actually choose the shortest path, causing performance issues for some users.

How does the picture improve with SPB?

With an SPB-based network, layer 2 services can be distributed throughout the enterprise painlessly. The problems of a traditional VLAN based network disappear. In an SPB network, a new location for a service is provisioned at the edge of the network – the rest happens automatically. This significantly speeds up deployment and reduces the risk of error. Another benefit with SPB is that ALL links are used, and the SHORTEST path is always chosen. No more idle links since no more spanning tree.

SPB farewell spanning tree

SPB is supported today in OmniSwitch 10k, OmniSwitch 6900 and the OmniSwitch 6860, allowing SPB to exist from the core to the edge. There's a great white paper talking about how you do that migration painlessly. And our customers are getting it too -- folks at Abilene Christian University have adopted SPB for a "simplified, more scalable and bandwidth-optimized network". The Universidad de Extremadura is another example of the customers from different regions and verticals who are seeing the benefits of SPB. Take a look and see if it's time for your network to bid farewell to spanning tree!

 

About the author
Rob Hemmerich

Rob Hemmerich

Director, NA Business Development, ALE

Rob Hemmerich has worked in the telecommunications industry for over 20 years, holding diverse roles in sales, marketing, program management and software development.

Twitter
Related Content
01-Jul-2020
blog-pageheader-1200x299 Has remote working become YOUR new normal?

As the pandemic circled the globe it quickly became evident that organizations needed to react rapidly to enable their teams to begin working remotely.

29-Jun-2020
blog-pageheader-1200x299 University delivers Wi-Fi in a crisis: A student PoV

Students get a semblance of ‘normal’ as CSUSB expands Wi-Fi to student parking areas to help with on-line learning during the ongoing health crisis.

11-Jun-2020
Blog page header Healthcare1 Stop the bleeding of nurses leaving using asset tracking

Healthcare providers need to leverage technology, such as asset tracking, to prevent equipment loss and free nurses and others from administrative tasks

11-Jun-2020
blog-pageheader-1200x299 Technology is vital to business revival in hospitality

Business continuity and digital transformation are fundamental to the resurgence of the hospitality industry in this post-health crisis era.

03-Jun-2020
blog-pageheader-1200x299 Smart city projects require culture change and user adoption

A smart city project can use innovation to set strategic priorities, increase process efficiency, improve transparency and boost the local economy.

02-Jun-2020
blog-pageheader-1200x299 Rediscovering human value in enterprises in times of crisis

The Place of the Human in today’s challenging business situation