WANs - How to maximize your bandwidth...

Overview

Wikipedia Definition of a WAN or Wide Area Network:If you already know the definition and want to dive into the next section (MPLS), please scroll down:

A WAN is a computer network that covers a broad area (i.e., any network whose communications links cross metropolitan, regional, or national boundaries [1]). Or less formally a network that uses routers and public communication links [1]. Contrast with personal area networks (PANs), local area networks (LANs), campus area networks (CANs), or metropolitan area networks (MANs) that are usually limited to a room, building, campus or specific metropolitan area (e.g., a city) respectively. The largest and most well known example of this type of networking is the Internet or the World Wide Web.

WANs are used to connect LANs and other types of networking systems together, so that users and computers in one location can communicate with users and computers in other locations. Many WANs are built for one particular organization and are private to that organization.

Others, built by Internet service providers, provide connections from an organization's LAN to the Internet. WANs are often built using leased lines from a carrier such as AT&T, Verizon, BT, etc. At each end of the leased line, a router connects to the LAN (local area network) on one side and a hub within the WAN on the other. Leased lines or circuits can be very expensive. Instead of using leased lines, WANs can also be built using less costly circuit switching or packet switching methods.

Network protocols including TCP/IP deliver transport and addressing functions. Protocols including Packet over SONET/SDH, MPLS, ATM and Frame relays are often used by service providers to deliver the circuits that are used in WANs. X.25 was an important early WANSACHMO protocol, and is often considered to be the "grandfather" of Frame Relay as many of the underlying protocols and functions of X.25 are still in use today (with upgrades) by Frame Relay.

First things first...Yeah, I know...definitions are boring but it will give you a basic understanding before we go any further:

Wikipedia definition of MPLS: In computer networking and telecommunications, Multi Protocol Label Switching (MPLS) is a data-carrying mechanism that belongs to the family of packet-switched networks. MPLS operates at an OSI Model layer that is generally considered to lie between traditional definitions of Layer 2 (data link layer) and Layer 3 (network layer), and thus is often referred to as a "Layer 2.5" protocol. It was designed to provide a unified data-carrying service for both circuit-based clients and packet-switching clients that provide a datagram service model. It can be used to carry many different kinds of traffic, including IP packets, as well as native ATM, SONET, and Ethernet frames.

MPLS or Multi Protocol Label Switching is an IETF–defined protocol that is used in IP traffic management. Basically, it provides a means for one router to pass on its routing priorities to another router by means of a label and without having to examine the packet and its header, thus saving the time required for the latter device to look up the address for the next node. It can also facilitate Quality of Service (QoS). QoS provides some guarantee of performance such as traffic delivery priority, speed, latency, or latency variation. Delivery of good-quality audio or video streams typically requires QoS capabilities. Now that the MPLS technology and networking systems have matured from their initial release approximately 3 years ago, it has become a very cost effective solution to replace existing frame relay and Internet based VPN networks.

The cost of VoIP (Voice over Internet Protocol) and video conferencing continues to drop and is becoming more affordable for even small businesses. MPLS creates a perfect fit to enable mission critical applications such as VoIP to run across the enterprise with the reliability. QoS (Quality of Service) inherent with the MPLS Network ensures the delivery of latency sensitive protocols such as VoIP and Citrix etc.

Now enterprises can begin to take full advantage of these applications with piece of mind MPLS offers many advantages over existing Wide Area Networking technologies. Listed below are many of the key reasons why MPLS is fast becoming the Wide Area Networking technology of choice.

• Cost –To the benefit of the customer it is far less expensive for the carrier to maintain the IP MPLS WAN infrastructure than it is to maintain existing Frame Relay and ATM WAN infrastructures. Most if not all of our customers are quickly moving to MPLS WANs for this very reason.
• Any to Any Connectivity –The old hub and spoke network design is outdated in today’s world. More and more remote locations need to communicate via VoIP or Video Conferencing. With MPLS WANs, the network is the hub and your corporate headquarters is just another remote location.
  
• Quality Of Service – MPLS WANs allows the carrier to mark packets and give them priority from one end of the Wide Area Networked system to the other. This is critical, in today’s network as more and more web based applications hog the available bandwidth. Latency sensitive applications such as VoIP, Video Conferencing, Citrix, and AS400 traffic need prioritization in order to work most efficiently across the WAN.
• Simplicity & Scalability – Because the carriers MPLS WAN becomes the hub, you never have to worry about building any more PVCs (Frame Relay), SVCs (ATM) or VPN tunnels as the enterprise wide area network expands. In many cases, all that is needed is a basic Cisco router with static routing to add a new location to the MPLS wide area network.
• Disaster Recovery & Business Continuity – With the flexibility of IP networking and the any to any connectivity of MPLS WANs, it is easier to create a cost effective Disaster Recovery solution using one of your existing remote locations; rather than using expensive hosting facilities and outsourced business continuity solutions such as Sunguard or Navisite.
• Voice over IP (VoIP) – Having the capability of the carrier to provide the Quality of Service (QOS) is CRITICAL for voice over IP to work properly, this QoS can give IT Departments a level of confidence that this will be a viable technology.
• Network Security – Because MPLS WANs only run across the carrier’s wide area network and is limited by routes to each of the customers location, it is by default a very secure network without the need to purchase, enable, and maintain high end security protocols such as IPSEC on the customer premise equipment (CPE). This simplicity allows the customer to focus on securing web connectivity and the LANs.

For these reasons, many businesses are quickly embracing MPLS as the WAN technology of choice. The flexibility and simplicity of the MPLS WANs allows the IT staff to focus on projects that increase productivity and the bottom line.

Wikipedia definition: "WAN optimization products seek to accelerate a broad range of applications accessed by distributed enterprise users via eliminating redundant transmissions, staging data in local caches, compressing and prioritizing data, and streamlining chatty protocols."

Ok, well it sounds interesting but I think we need to dive into this definition in more detail to truly understand what this means and how it effects you. As you already know, wide area networks are generally extremely slow links (compared to LAN speeds) and connections that interconnect branch offices, vendors, partners as well as mobile workers and telecommunters. Even with bandwidth costs dropping on a daily basis, these links and connections are extremely expensive.

As corporate applications become more and more critical to the survival and growth of the business' bottom line, IT departments face tough decisions about how to deliver more applications with better performance to all of the end users across the wide area networked system. These concerns have slowly grown to be huge challenges for IT managers and directors over the past 2 years. This is why WAN optimization and application acceleration is so critical to the future of wide area networks.

In the past, the myth that "ordering more bandwidth will solve my problems" was the general response when a business was facing slow application performance across the wide area networked system. This response was due in part because there were limited options for IT staff to try and improve application performance without increasing bandwidth. This problem has created the opportunity for someone to develop an alternative solution to improve application performance and enhance the use of the current WAN bandwidth without increasing bandwidth.

For more information on WANs or MPLS or WAN Acceleration solutions or if you would like to evaluate Riverbed's WAN optimizers in your production environment free of charge, contact us.

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Learn more about WAN Acceleration: watch Jack's story...