Thursday, March 6, 2014

The Critical Role of the Business Edge Network

The Service Provider’s Challenge
Businesses are increasingly using service providers to host critical applications and data in order to better control the security and availability of the data and to mitigate the expenses associated with hosting and serving data locally to the entire business user base. They access these applications and data over the service provider’s business edge network. This creates a challenge for the service provider, because their customers measure the success of the network by its ability to handle critical data and provide a superior user experience. With more and more applications and data centralized, the importance of the network, and its role in the success of the business, becomes ever more critical.

Market forces have created an environment of unpredictability for the service provider. Mobile devices, new applications, and the flood of new content place a direct strain on the business edge network, forcing the business and the service provider to address the network in creative ways. Maintaining and evolving the end-user experience is critical to the success of the network and key to enabling the service provider to meet its business goals.

The business user base, places considerable expectations on the network. Users expect their business e-mail and voice over IP calls to work flawlessly, while also expecting mobile video and applications to perform seamlessly. The impact of network performance is real and must be factored into the design of future business networks. This challenges the business edge provider to optimize the design and find ways to reduce the cost in the face of the increasingly complex and growing demand for a high-quality end-user experience.

Does E-VPN Spell the End for OTV?

If you are considering how best to do Layer 2 stretch for virtual machine mobility, then you might be considering Overlay Transport Virtualization (OTV). OTV designed by Cisco to offer L2 stretch with what they said was an easy to deploy protocol. It was only available on the Nexus switching product line, which didn’t support VPLS/MPLS. Until recently MPLS/VPLS was Juniper’s recommended technology for network segmentation and Layer 2 stretch, which Cisco also offers on the ASR routers.  We’ve recently announced E-VPN, which is MPLS/VPLS based and brings all of the benefits of VPLS and then some. Cisco has announced E-VPN on the ASR router as well. Now that E-VPN is available, maybe it’s time to consider your best option. Let’s take a look at why OTV isn’t the best choice for VM mobility and why E-VPN is.

Why OTV was Invented
OTV has been in the Cisco’s news announcements, highlighted at Cisco Live and featured in several Cisco blogs. It’s something I’ve been meaning to cover along with my blogs on LISP and VXLAN as these all get discussed together as parts of a complete solution for live VM migration. Cisco first announced OTV on Feb. 8, 2010. Overlay Transport Virtualization is a Cisco proprietary protocol which provides Layer 2 extensions, over IP, to interconnect remote data centers.  Cisco claims that the OTV is a simpler technology than MPLS/VPLS, which is a standards-based and proven technology for network segmentation and Layer 2 Extension.  They said that OTV can be provisioned within minutes, using only four commands, and that it provides increased scalability (however without seeing the independent studies we don’t know if this is true).  It was only offered it only on the Nexus 7000, which didn’t offer MPLS/VPLS technology. With OTV, Cisco pushed yet another proprietary protocol that is not as well proven as standards-based MPLS/VPLS or the newer E-VPN. Cisco supports VPLS on the ASR router so it is curious that they did OTV on the Nexus which doesn’t sit at the right place in the network to do L2 Stretch. The Cisco ASR, like the Juniper MX, is meant to do L2 stretch at the data center edge, not in the data center core where the Nexus switches sit.