Wide Area Networks (Internetworking Your Library Branches)

Wide area networking refers to the interconnection of geographically dispersed offices separated by public rights-­of­-way. The Internet is actually a huge wide area network (WAN), and if your branches are all online, they’re technically already part of the same WAN. However, the Internet lacks the reliability, security and bandwidth that companies need for certain sensitive data and critical applications. In a library context, circulation records, cataloging records and financial records shouldn’t be sent over the public Internet unless they’re encrypted. Moreover, since they’re critical to the work your staff does, you don’t want your colleagues twiddling their thumbs while a batch of cataloging records fights its way upstream against all the YouTube videos and file downloads. So most multibranch library systems eventually create a private WAN. These WANs often do carry Internet traffic for staff and patrons at the branches, but you can control that traffic, keep it separate from staff data and assign it a lower priority than your cataloging and circulation records.

Why Is Your Wide Area Network Important?

  • Better service. The faster you can transfer circulation and cataloging records between branches, the better your service to patrons. If a patron sees a book in the catalog that seems to be available and places a hold on it, she’ll be disappointed to find out an hour later that the book was actually checked out.
  • Improved staff productivity. Obviously, the more time staff has to wait for cataloging records and other files, the less productive they’ll be.
  • IT savings. One of the biggest drains on your IT budget and your tech support staff is the need to drive back and forth between the main library and the branch libraries. Once you add up the gas, the maintenance of the cars and the time your staff spends on the road, you’re often looking at thousands of dollars a week to troubleshoot routine software problems. Therefore, IT departments are doing as much work as they can over the library’s WAN, and they rely on high­-bandwidth, low-­latency connections. For example, IT staff often use remote desktop software to troubleshoot computers at the branches. Where the bandwidth is sufficient, IT departments are using enterprise software such as Norton Ghost and Active Directory to send software updates and disk images over the WAN. If the operating system on a remote PC gets corrupted, they can reimage the entire computer from the main branch.
  • Centralization and consolidation savings. We usually talk about WANs when we’re discussing the transfer of data back and forth between colleagues at remote locations or between software applications working on their behalf. However, WANs can also carry phone calls and ordinary Internet traffic. It depends a lot on local variables, but in many areas, it’s cheaper to send all your traffic (voice, Internet, cataloging records, etc.) over a single line headed towards the main branch. The routers at the main branch then separate the traffic streams and send them all to their appropriate destination. Obviously, the central location will need a higher-­bandwidth Internet connection to handle the traffic coming from the branches, and you may need to upgrade the WAN connection at each branch location. However, the alternative often turns out to be more expensive. When each branch has multiple lines (one for phone service, one for Internet traffic and one for catalog records), the costs add up quickly.
  • Managing and prioritizing traffic. You have much more control over the data on your WAN than you have over standard Internet traffic. You can give high priority to circulation and cataloging records, voice traffic and other staff communication. It’s also easier to monitor and troubleshoot a private WAN.

Key Actions

  • Establish partnerships. Refer back to Internet Access and ISPs for information on ways to join (or create) local, regional and statewide cooperative networks. These cooperative purchasing and administrative agreements can save you thousands each month. We also discuss ways to find consultants and advisors.
  • Choose one provider. If possible, choose a single service provider for your entire WAN. This might be impossible, depending on the network coverage in your area, but whenever service providers have to exchange traffic, delays get introduced and it’s harder to guarantee levels of service.
  • Think about the kinds of traffic your WAN will carry. As we mentioned previously, if the links going out to the branches are wide enough, they can also carry Internet traffic and voice traffic. In other words, instead of purchasing a high-­speed Internet connection for each branch, you buy a really big pipe at your central location, and that pipe handles all the Internet traffic for your entire library system. Of course, all the branch traffic has to go across the WAN before it gets to the Internet, but as long as those WAN connections are wide enough and fast enough, they won’t add a significant delay. Also, you’ll have to buy a larger Internet connection at the main branch, but that’s often cheaper than maintaining a separate connection for each branch. Of course, this creates a single point of failure for your whole system, so you should have a backup Internet connection at the main branch.
  • Talk to staff, patrons and IT. Think carefully about the applications you’re using now and the ones you’ll be introducing over the next few years. Ask staff what kinds of data they transfer between branches and whether they’re satisfied with the perceived speed of these transactions. If you’re considering the implementation of the remote administrative programs mentioned previously (e.g., Norton Ghost or Microsoft’s System Center Configuration Manager), talk to the vendors and your IT staff to see how much bandwidth you’ll need between branches.
  • Use a centralized phone system. If you don’t already have a centralized phone system, you can decrease your overall costs and increase your service and functionality by centralizing, but there’s a whole lot of planning and expertise and up-­front costs that go into that sort of a switch, so you’ll need to talk to an expert.

Shared Lines vs. Leased Lines

  • A shared line or “best effort” connection refers to a data link between two locations over shared circuits and shared equipment. In other words, the service providers who create the connection will do their best to forward your traffic to its final destination, but they won’t make any guarantees regarding how long it will take to get there and how much bandwidth gets allocated to your data. Most residential Internet service plans fall into this category.
  • With a leased line, on the other hand, the network service providers manage the connection between the sender and the receiver to ensure a certain level of service in terms of latency and bandwidth. Leased lines are sometimes referred to as private lines, dedicated lines or point-­to­-point lines. Also, service providers often refer to the underlying network protocol. In other words, T-­1 lines, Frame Relay circuits and Ethernet connections are all leased lines, though they vary quite a bit in terms of their cost, availability and performance.

Other WAN Considerations

  • WAN topology: This refers to the layout and interconnection of the end units (or nodes) in a network. Most library systems use a hub­-and­-spoke topology for their wide area networks. In other words, the branches all link to the central library, but they don’t link directly to one another. They can still communicate, but all that data goes through the networking equipment at the main branch first. Some businesses use a mesh topology where every branch office is connected to every other branch office, but this type of WAN is usually more expensive and more complicated to administer, and there’s not much need for it in the library environment.
  • WAN management: If you have skilled network administrators on staff, you might be able to handle the configuration of routers, switches, firewalls and other devices. However, each WAN protocol has its own equipment, its own set of concepts, its own terminology and its own rules, so it’s often easier and cheaper in the long run to pay your service provider and let them manage your WAN.
  • WAN protocols: There are dozens if not hundreds of networking protocols that play a role in wide area networking, but you can usually ignore the details of how each one is implemented. Also, you often use several of these protocols in combination over the same wide area link. Furthermore, the best protocol in a given situation depends mostly on the local ISPs and the extent to which they’ve invested in the necessary circuits, equipment and expertise.
    • Ethernet, SONET/SDH, FTTx, ATM and MPLS have good reputations with regard to bandwidth, reliability and the ability to handle time­-sensitive traffic, but they’re expensive and they’re not available in a lot of places.
    • Frame Relay has been around for a long time; therefore, it’s sometimes the only available option, but it wasn’t designed to handle real-time voice and video traffic.
    • ISDN has also been around for quite awhile, but it’s being replaced by faster, cheaper protocols. Setup, configuration and management of an ISDN connection can also be very complicated.
    • T­-1 lines (and variations such as T-­3 lines) are a standard, widely available option, and they can carry both voice and data.
  • VPNs: Increasingly libraries are building their WANs across the public Internet. In other words, they don’t buy expensive point-­to­-point connections, but instead they purchase a standard high-­speed Internet connection at each branch. They then use VPN (Virtual Private Network) devices to encrypt their sensitive cataloging and circulation records. In effect, they’re creating a private, encrypted tunnel within the wide-open, chaotic Internet. Although this option is cheaper than leasing point-­to-­point connections in some areas, you may have less control over the performance and prioritization of your traffic. Also, you might find that there’s a high learning curve associated with configuring and maintaining VPN devices.
  • Reliability and Service Level Agreements (SLAs): Most leased lines include assurances with regard to “uptime” and other metrics. In other words, your ISP might guarantee that 99.9 percent of the time your connection will work and they promise to refund some of your money if they fail to meet that target. Also, they often make promises with regard to throughput, latency, dropped packets and other measures. These promises are usually captured in a Service Level Agreement (SLA). Bear in mind that your ISP only makes these promises with regard to service between your building and the edge of the ISP’s network (where it connects to the Internet backbone). Beyond that they have no control. Also, if you have several connections from the same provider, your ISP may make assurances about average, across-­the-­board metrics. For instance, if they promise a monthly average of 99.8 percent uptime across ten high-speed connections, that leaves them a lot of leeway. Your main Internet connection could be down for roughly 14 hours a month and they’d still be within the terms of the SLA. Pay close attention to this type of detail. An example of an SLA can be found at Speakeasy.net.

Stories from the Field

The other technology that we’ve implemented here at one of our branch libraries, and are starting to phase it in here at central library, is Voice over IP telephones, and that provides us [with] a cost savings. We are able to put the telephones on the same network as our data — as our computer network — so that is saving us an infrastructure cost. And from what I have been told, the Voice over IP technology could cut down on the costs of long­-distance phone calls also. It’s sharing the same bandwidth as the computer network, so you need to make sure you have sufficient bandwidth for everything that you’re doing there. You do not want everything to go down when somebody starts a streaming video broadcast on one of their computers.

Thomas Edelblute
Anaheim Public Library, CA

Our branches are on the same wide area network and different subnets, but we’re going away from that model. We are going to put individual connections in different libraries because the more you send traffic through a central location, the slower things get. Right now, the smaller libraries have 256-Kbps connections, and the first of July they’re going to go to T­1s. And then we are going to put in a fiber connection with two T-­1s here at the main branch.

Our ISP actually owns our routers, so they do all the router maintenance for us. And we go through Merit, which is an ISP for nonprofits in Michigan. They are really easy to work with, and we have never had a problem. This will be our tenth year with them. Actually, the cost of bandwidth went down for us when we went from the 256-­Kbps lines to the T-­1s this year. It will actually cost less for them to have the T-­1 than it was to have the 256. As a consortium, we buy Internet access, and our libraries can buy into that if they want to. But we don’t have all 20 of the libraries that we support doing that.

We have five libraries that don’t come back through the main branch — they have their own firewalls. And we have about ten that actually come through our firewall first before they go out to the Internet.

Jean Montgomery
Upper Peninsula Region of Library Cooperation, MI