* What you'll learn at our WAN optimization technology tour
The Network World Technology Tour season is well underway and preparations are now being made for our educational seminars about WANs. The free seminars, which will travel to four cities over the next two weeks, will examine the different methods you can use to optimize your WAN.
The tour will be moderated by Jim Metzler, vice president of Ashton, Metzler and Associates and co-author of our WAN newsletter. Jim has been discussing some of the WAN optimization methods in recent issues of the WAN newsletter and you can check out the archives through this link: https://www.nwfusion.com/newsletters/frame/index.html . I caught up with Jim as he prepares for the tour to ask him explain the different WAN optimization methods and to learn about the other issues that will be discussed at the event. Here is our Q&A:
1. Compression, caching, TCP acceleration and wide area file services, have been named as techniques that can reduce the cost of WANs. What are these techniques and how should they be deployed?
The basic function of compression is to reduce the size of a file of data to be transmitted over a WAN. Part of the challenge associated with compression is that not all file types can be easily compressed.
There are several ways that caching is implemented. Most browsers contain a local cache for Web pages that have already been accessed. A proxy cache acts similar to a browser cache, but sits at the WAN edge and caches requests from many users, instead of just one. Finally, data center (or reverse proxy) caches offload servers and help speed content out of the data center.
TCP acceleration focuses on overcoming the limitation of the TCP window size. The issue here is that when you’re sending a packet of information over the network, a local copy of the information must be maintained until you get an acknowledgement that the information was received at the other end. If an acknowledgement is delayed for whatever reason, then the transmitting side must wait until the window opens again.
The goal of Wide Area File Services (WAFS) is to make file access over the WAN perform as it would over the LAN. In most cases, this means trying to make chatty file access protocols such as Common Internet File System (CIFS) and Network File System (NFS) that were designed to run over a LAN, run over the WAN without a notable delay.
2. How is applications performance improved by using QoS?
Each of the performance enhancement techniques described above functions in a manner that is logically equivalent to a one-time bandwidth increase. However, having a one-time bandwidth upgrade does not provide any guarantees that an application will receive the network resources that it needs to perform at acceptable levels. This requires some form of QoS – such as what is available from MPLS or some form of queuing.
3. Why can it be advantageous to deploy MPLS in private WANs without using a service provider?
This approach is appealing to companies that satisfy three key criteria. One, they do not want to turn control of their network over to a service provider. Two, they want to offer a range of services to their users in a manner similar to how carriers offer multiple services to their customers. Three, they are looking to deploy a network that is highly flexible and robust, and which enables both the consolidation of technology and traffic types, as well as the isolation of traffic.
4. What other WAN optimization techniques will attendees learn about at the event?
We will hear about application specific optimization techniques and architectures that unify what could be disparate optimization techniques into a coherent whole.
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The tour will travel to Atlanta, Philadelphia, Denver and Los Angeles, beginning April 19. For more about the tour and to apply to attend, please go to: https://www.nwfusion.com/events/wan/index.html
To continue your education about WAN issues, check our WAN Services Research Center (https://www.nwfusion.com/topics/wan.html) where you’ll find breaking WAN news, white papers, Web casts and Special Reports. In addition to Network World’s WAN newsletter, which Jim co-authors with Steve Taylor, president of Distributed Networking Associates and publisher/editor-in-chief of Webtorials, you should also check out our ISP News Report (https://www.nwfusion.com/newsletters/isp/index.html) and VPNs (https://www.nwfusion.com/newsletters/vpn/index.html) newsletters.
