Planning for WINS Client Network Traffic

WINS clients generate the following types of network traffic:

When a WINS-enabled client starts on the network, it sends a name registration request for the computer name, user name, domain name, and any additional Microsoft network client services running on the computer. In other words, when a WINS client starts on the network, it generates a minimum of three name registration requests and three entries in the WINS database.

A Windows NT Server-based WINS client usually registers more NetBIOS names than other WINS-enabled clients. The name registration requests generated by a computer running under Windows NT Server include the following:

WINS Client Traffic on Routed Networks

When planning for WINS client traffic on large routed networks, consider the effect of name query, registration, and response traffic routed between subnets. Name requests and responses that occur at the daily startup of computers must pass through the traffic queues on the routers, and may cause delays at peak times.

Daily Startup of WINS Clients

An active WINS client name registration in a WINS server database is replicated to all pull partners configured on that WINS server. After some time, the active name registration is replicated to all WINS servers on the network.

When the WINS client is turned off at the end of the day, it releases the name. When the computer is started the next morning, the WINS client registers the name again with the WINS server, and receives a new version ID. This new, active name registration entry is replicated to the WINS server's pull partners as on the previous day.

Therefore the number of name registration entries that are replicated each day is roughly equivalent to the number of computers started each day times the number of NetBIOS names registered at each computer.

On large networks (50,000 or more computers), the biggest traffic load may be the name registration requests generated when WINS clients start on the network.. Fortunately, the difference in time zones in large enterprise networks provides some distribution of this WINS client startup load.

Roving User

When a user stops the computer and then moves and starts the computer on a different subnet with another primary WINS server, name challenge traffic is generated. Typically, the name registration request is answered with a Wait for Acknowledgment message (100 bytes), and the new WINS server (assuming the active entry was replicated) challenges the IP address that is currently in its database for this name (Name Query packet, 92 bytes). When there is no reply, as can be expected in this case, the WINS server repeats the challenge two more times and then updates the name registration entry with the new IP address and a new version ID. The new version ID indicates that the entry must be replicated from its new "owning" WINS server to other WINS servers on the network.

Estimating WINS Client Traffic

You can estimate WINS client traffic based on the behavior of the WINS clients as described in the preceding sections. However, when estimating WINS client traffic, you must also consider the network topology and the design or configuration of the routers in the network. In some cases it may not always be possible to predict the traffic load on a specific network router because the routers may be designed, or configured, to autonomously route traffic based on factors other than traffic load.