Intel 7400 manual Gaming protocol, Round-trip network latency tests

White Paper Consolidation of a Performance-Sensitive Application

Client 1

	40–200 bytes UDP
Game Player		Game Server
	2,000 bytes UDP

Client 8

1 GbE

Force 10 S50*	10 GbE	Native
		Server

1 GbE

Figure 9.. Game network protocol overview.. Figure 10.. Native lab test setup..

Gaming protocol

How does this gaming protocol work? A player sends a UDP packet of 40–200 bytes in size to the game server. The game server receives the packets, does its own processing, and then updates all the players by sending a 2,000-byte UDP packet (as represented in Figure 9).

We know that the virtualization will increase the round-trip network latency, but we are not sure by how much. In theory we also know that enabling VMDq and NetQueue will improve the network latency. We searched both internally and externally for data related to the impact of virtualization on latency sensi- tive applications, but we were not successful. Therefore, we decided to do our own tests in Intel labs.

Round-trip network latency tests

In order to run the round-trip network latency test, we used the micro-benchmark Netperf 2.4.4, the UDP latency test and the ESL workload, which consists of UDP packets. The following three scenarios are being compared here:

1.Native

2.Virtualized with VMDq/NetQueue

3.Virtualized with no VMDq/NetQueue

Scenario 1: Native

The setup and configuration, as shown in Figure 10, includes eight clients connected to eight 1-GbE ports of a 1G/10G link aggregation switch (Force 10 S50*) and the Intel Xeon processor 7300 server connected to 10G port of the switch via Intel® 82598 10GbE CX4 NIC. SLES10 SP1 is the operating system installed on all the clients and servers, and there are eight parallel streams of UDP latency tests being run from the clients to the server.

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