By Daryl Jenson Director of IT Viewpoint Construction Software INTERNET CONNECTIONS FOR VIEWPOINT CLOUD COMPUTING The network plays a critical role in application performance for Cloud based customers. If you are depending on it for your primary computing activities, it becomes the oxygen supply for productivity within your company. Poor network bandwidth planning or no planning at all may result in poor cloud application performance and unhappy users. The network design and bandwidth should support current requirements as well as some planned growth since Internet contracts are signed for multi-year terms. The reality in most business environments is that Internet usage can vary greatly throughout a day and can reflect a wide range of time spent on the Web between users, making it difficult to estimate hard numbers. With that in mind, this document will provide the best possible information and recommendations on how to estimate reasonable requirements. SIZING UP YOUR BANDWIDTH REQUIREMENTS As you might expect, each company s requirements will vary depending on the size of the organization or number of active Internet users. What is perfect for one may not be enough for another; however there are some simple ways to compute average bandwidth estimates. It s important to consider all company activities that require Internet usage various activities can cause higher and lower bursts of
traffic. For example, printing sends a sustained stream of data back to your workstation so that it can be printed locally. If someone in your organization is printing large month-end reports in the middle of a productive workday, there could be a serious, noticeable drag on the Internet speed experienced by other users. Things get even more bogged down if several users are printing documents at the same time or if unplanned bursts of company wide Internet activity occur. In these cases, providing an over-supply will help performance for peak activity periods. It can be very beneficial if you are able to obtain reports from your ISP on average and peak usage throughout a day, week and month to confirm high periods of use. Another factor in Internet performance is latency, (the time it takes for a keystroke to traverse the Internet and hit the target server). As latency increases, performance decreases. Latency and bandwidth are functions of the Internet Service Provider (ISP) that you choose along with location. Note that various Internet suppliers are rated as Tier 1, Tier 2, or Tier 3 depending on whether they own their own networks, their size, and a number of other business characteristics. Many ISPs seeking your business may declare themselves Tier 1 so do your homework to avoid being misled. Tier 1 Usually indicates that the ISP owns their network. The question becomes what geographic area does their network cover and what are their guarantees relating to latency and sustained throughput. How long does your connection stay on-net before having to traverse other owners networks through pier-points to get to the final destination. The number of pier-points along the path are often called hops. The fewer hops, the better the performance. Tier 1 Internet providers usually provide the fewest hops to get to a destination. Tier 2 and 3 These providers are smaller regional companies that are reselling services from the larger providers.
User activities greatly affect bandwidth usage. The following are bandwidth estimates as listed by Citrix for various types of Internet usage: APPLICATION (MEDIUM WORKLOADS) Office-based Internet Printing Flash Video Standard WMV Video High Definition WMV Video Idle NATIVE CITRIX XENDESKTOP 43 kbps 85 kbps 555-593 kbps 174 kbps 464 kbps 1812 kbps Based on active applications * Citrix white paper XenDesktop Planning Guide: User Bandwidth Requirements. MAKING IT FIT: OUR RECOMMENDATIONS The Citrix XenDesktop application is estimated to require about 31 kbps per user, however Viewpoint recommends 80 kbps per user as a reasonable average figure to use when calculating how much bandwidth is needed. That figure provides some buffer for the highs and lows that might be experienced throughout a day. Of course this is just a recommendation since usage other than your Viewpoint Citrix connection can totally monopolize your company s bandwidth.
Large Office: For a larger office, you should consider providing two ISPs with failover setup so that if one provider goes down, the other takes over. How large is large? You decide! Remember, the Internet bandwidth supply is like oxygen, and you have to determine the cost to the business should one provider go down at an inopportune time. Home or Field Offices: These locations are often reliant on cell or home data connections with wireless type access. The quality of these connections are totally dependent on location and quality of the cell or home data signal. Remember that the Citrix XenDesktop client itself can run well with 31 kbps. Cell connections can easily exceed that for a single user but it is totally dependent on location and signal strength. Evaluating ISP s: When evaluating Internet Service Providers (ISP s), determine whether they are a Tier 1, Tier 2, or Tier 3 provider. Make note of how strong the provider is in your area and if possible, find out how many hops a signal goes through to reach the Viewpoint application cloud host along with the latency figure. In general latency, under 80msec is considered acceptable but anything over a 100msec is probably going to cause problems - 20-65msec latency would be considered great. Sample Calculation: 10 users: 10*80kbps = 800kbps 100 users: 100*80kbps = 10,000kbps = 10 Mbps Connections: A T1 Internet connection is a typical unit delivered as 1500kbps or 1.5Mbps. For 10 users, a T1 Internet connection would provide ample bandwidth for Citrix, and would even provide an oversupply for others. If your users do a lot of other Internet work; downloading, streaming, video watching, etc., it might
be wise to provide a large over-supply opting for 5 or even 10 Mbps circuit. These increments are becoming available at very reasonable rates depending on location. Note that a company of 100 users would require a 10 Mbps circuit but might opt for a 20 Mbps circuit to provide for other general access and all peak periods. The additional amount purchased will probably depend on the additional cost of the bandwidth verses the value provided. Often, ISP s can provide pure network connections into your office in increments as 5 Mbit, 10 Mbit, 20 Mbit, 50 Mbit and up. The type of connection and suppliers available are dependent on your location. At Viewpoint Construction Software, we currently have two ISP s with automated failover between 45 and 50 Mbit circuits. This provides a large oversupply based on average statistics; however we consistently have peak usage into the 30-42 Mbit range. The oversupply provides failover, as well as service during all peak periods and additional bandwidth for cloud based data backups. One source for finding ISP s in your area along with some rating information can be found at this link: http:// www.dslreports.com/ For more information, please contact us at productinfo@ viewpointcs.com or 800-333-3197. Visit us at www.viewpointcs.com/cloud