When looking at WAN optimization and branch consolidation in the private cloud, enterprises need to consider service integration -- such as firewall virtualization, infrastructure segmentation and next-generation WAN techniques -- and the limitations of these services.
Chapter 3, “Next-Generation WAN and Service Integration,” from the book Private Cloud Computing: Consolidation, Virtualization, and Service-Oriented Infrastructure , provides an in-depth look at private cloud computing and the WAN, helping WAN managers and network engineers understand integration of service elements such as firewalls and server load balancers (SLBs), as well as next-generation WAN technologies. Read an excerpt from the chapter below, or download a free PDF of the complete book chapter: Next-Generation WAN and Service Integration.
Adapted from Private Cloud Computing: Consolidation, Virtualization, and Service-Oriented Infrastructure, by Stephen R. Smoot and Nam K. Tam (Published by Morgan Kaufmann).
The next-generation enterprise WAN
The modern-day WAN services offered by providers are typically in the form of IP services or L2 circuits. IP services include L3 VPN or the Internet. L2 circuits include Time-Division Multiplexing (TDM7), Frame Relay, Asynchronous Transfer Mode (ATM8) or Synchronous Optical Networking (SONET9). To maintain end-to-end multi-VRF tenancy to the remote sites, it is necessary to extend L3 segmentation from the enterprise DC (fabric module) over these WAN services to the end-user module. This brings up a list of next generation WAN refurbishment techniques, such as the following:
- Multi-VPN service from a service provider (SP)
- Multiprotocol Label Switching (MPLS10) over L2 circuits
- Dynamic Multipoint Virtual Private Network (DMVPN11) per VRF
- MPLS VPN over DMVPN (hub and spoke only)
- Carrier supporting Carrier (CsC12)
- MPLS VPN over IP using Layer 2 Tunneling Protocol version 3 (L2TPv313)
There are some limitations for CsC and MPLS VPN over L2TPv3 deployments. The main barrier against adopting CsC is its scarce offering by providers. It is hardly ever offered to enterprises. For MPLS VPN over L2TPv3, it is supported only in a limited subset of most enterprise product lines, making it a less generalized solution. These two particular solutions are not discussed further in the later subsections. The techniques discussed in this section only pertain to the deployment between the enterprise DC and the remote branches across a WAN. The deployment between enterprise DCs across an MAN is covered in Chapter 7.
©2012 Elsevier, Inc. All rights reserved. Printed with permission from Morgan Kaufmann, a division of Elsevier. Copyright 2012. For more information on this title and other similar books, please visit www.mkp.com.
→ To read more about WAN optimization and consolidation in the private cloud, download a PDF of Chapter 3, “Next-Generation WAN and Service Integration.”
About this book: Private Cloud Computing: Consolidation, Virtualization, and Service-Oriented Infrastructure offers a wealth of information on private cloud computing, including cloud security and management, real-world case studies, next-generation data center architectures and solutions for consolidation. The book describes how to create cost-saving designs and increase flexibility of the enterprise, while maintaining control of an internal network.
About the authors: Stephen Smoot is the senior vice president of technical operations at Riverbed Technology. Nam Tan CCIE #4307 (RS, SP) is the lead network architect of advanced network engineering at Riverbed Technology.
This was first published in December 2011