When planning the layout of a SharePoint farm, it is important to remember that the farm not only communicates with SharePoint users but also requires communications within the farm (to each tier) and communications to other servers in the network (such as Exchange or Lync servers). Effective network infrastructure planning requires that each of these connection types be considered in the overall design.
Interserver and end-user communication
There are two distinct types of network communication present within a SharePoint farm: user facing and interserver. Communications between servers within the farm can be quite intense at times; during these times, users might experience diminished performance if both types of communication take place across the same network interface.
As a result, servers in the web and application tiers of a SharePoint farm should have two distinct network interfaces:
■■ The first network interface card (NIC) handles user requests, routing traffic back and forth to users.
■■ The second NIC handles interserver connectivity, routing traffic back and forth between the SharePoint servers (web and app tier) and the data tier.
Network latency and stretched farms
Latency and bandwidth are concepts that go hand in hand. The best way to understand the relationship between these two is to imagine driving on a freeway. The speed limit (bandwidth) relates to how fast the traffic can travel on the freeway, whereas the traffic congestion present on the freeway can cause the commute time (latency) for any one car to increase.
SharePoint farm servers should be connected to each other with a minimum connectivity speed of 1 Gbps. Although it is possible to achieve this connection speed over a wide area network (WAN) connection, the network latency (time taken for a byte to travel from source to destination) often exceeds 1ms. Microsoft requires that the latency between SharePoint servers and the content database be less than 1 ms apart.
Unfortunately for system administrators, this latency requirement also prohibits the members of any one SharePoint farm from being located in two data centers (no matter how closely located these centers are). All servers belonging to a server farm must be physically located in the same datacenter to be supported.
| EXAM TIP |
the connection speed between all SharePoint servers in a farm must meet or exceed 1 Gbps. additionally, the network latency between the web/application tiers and the data tier should be less than 1 ms.
Internet Protocol (IP) support in SharePoint 2013
SharePoint 2013 fully supports IPv6, the latest revision of the Internet Protocol. Microsoft recommends that you leave IPv6 enabled on your SharePoint servers; if your network does not support IPv6, IPv4 will be used as a default.
Thought experiment
Minimizing farm hardware expense
In the following thought experiment, apply what you’ve learned about this objective. You can find answers to these questions in the “Answers” section at the back of this chapter.
You are designing a small SharePoint environment to support 2000 users. Because this environment is heavily utilized for day-to-day operations and workflow, highavailability is a must. Additionally, there are several departments that make extensive use of features such as Excel Services.
You have rather stringent budget specifications and must weigh the value of purchasing server hardware against the cost of purchasing other equipment. What server layout approach should you propose and how might you address availability requirements?
