Network Virtualization using Extreme Fabric Connect

Network Virtualization Using Extreme Fabric Connect
© 2019 Extreme Networks, Inc. All rights reserved. 32
• Requirement to terminate a large number of I-SIDs on a per-access switch basis. Since Fabric Attach
leverages LLDP for service signalling, the Fabric Attach TLV cannot be larger than a given size.
Caution
LLDP’s TLV maximum size equates to the ability to request a maximum of 94 I-SIDs
with Fabric Attach and not more. Should there be a requirement for an access
switch to terminate more than 94 I-SIDs then the Fabric Connect mode could be
used.
• Availability of advanced UNI types on the access switch. Fabric Attach caters only for the most
common CVLAN UNI type. Use of the more sophisticated Switched-UNI and Transparent UNI
modes would require use of Fabric Connect mode.
Fabric Extend
Given the powerful service virtualization capabilities of the Extreme Fabric Connect architecture there was
a strong demand from the outset to be able to extend the same capabilities to the branch or between
geographically distant networks. This led to the development of Fabric Extend.
Fabric Extend is able to extend the SPB Ethernet Fabric, as an overlay, over the WAN. This then allows the
L2 and L3 VSN service types to be extended with ease all the way to the branch office using the same
powerful end-point provisioning of Fabric Connect.
Figure 9 Benefits of Extending Fabric Services with Fabric Extend
As depicted in Figure 9, this brings a number of important benefits. To start, the traditional WAN router is
no longer required as the WAN circuits can be directly connected to Extreme’s Fabric Extend capable
switching platforms.
Tip
With Fabric Extend the traditional WAN Routers are no longer required.
But the real benefit comes when there is a need to extend virtualization (typically in the form of L3 VSNs,
but L2 VSNs are also possible) all the way to the branch office. In a traditional WAN architecture, the only
way to provide separation for different user groups or tenants would be to purchase separate WAN
services for each tenant and map these to the customer’s VRF instances. This mapping needs to occur on
the WAN router, requires participation from the WAN operator, and thus hinders the ability to deploy those
services end-to-end on-demand as every new service would require touching the WAN routers and waiting
for the WAN provider to provision the new WAN service.