NTTTCP Full-Duplex Mode

The existing PERF-NETWORK-NTTTCP.json profile supports an optional DuplexMode parameter that enables bidirectional network throughput testing. In full-duplex mode, both nodes simultaneously send and receive traffic, producing separate TX and RX throughput metrics per direction.

• Network Suite Workload Details
• Client/Server Workloads

How Full-Duplex Differs from Half-Duplex

In the standard (half-duplex) mode, one node sends while the other receives. In full-duplex mode, each node runs two NTttcp processes simultaneously: one sender and one receiver. This results in 4 NTttcp processes total across the two systems.

Direction	Port	Client	Server
Forward	base port (default 5500)	Sender (-s)	Receiver (-r)
Reverse	base port + 100 (default 5600)	Receiver (-r)	Sender (-s)

Usage

# Half-duplex (default, unchanged behavior)
VirtualClient.exe --profile=PERF-NETWORK-NTTTCP.json --clientId=Client01 --layout-path=/path/to/layout.json

# Full-duplex (override DuplexMode parameter)
VirtualClient.exe --profile=PERF-NETWORK-NTTTCP.json --clientId=Client01 --layout-path=/path/to/layout.json --parameters=DuplexMode=Full

PERF-NETWORK-NTTTCP.json

The standard NTttcp profile now includes the DuplexMode parameter (default: Half). All existing scenarios work unchanged. Override with --parameters=DuplexMode=Full to enable full-duplex.

• Workload Profile

• Supported Platform/Architectures

  • linux-x64
  • linux-arm64
  • win-x64
  • win-arm64

• Supports Disconnected Scenarios

  • No. Internet connection required.

• Dependencies
  Same as the standard PERF-NETWORK-NTTTCP.json profile:

  • Internet connection.
  • The IP addresses defined in the environment layout for the Client and Server systems must be correct.
  • The name of the Client and Server instances defined in the environment layout must match the agent/client IDs supplied on the command line.
  • Ports 5500 (forward direction) and 5600 (reverse direction) must be available on both systems when using full-duplex mode.

• Profile Parameters
  The following parameter is added for full-duplex support. All other parameters remain unchanged.

  Parameter	Purpose	Default
  DuplexMode	Set to "Full" for bidirectional testing. Any other value (or unset) uses standard unidirectional testing.	Half

• Scenarios
  All existing NTTTCP scenarios support full-duplex mode. When DuplexMode=Full, each scenario runs both send and receive processes on each node. The existing scenario names are unchanged — the direction and duplexMode metadata in telemetry distinguish full-duplex results from half-duplex.

Workload Metrics

Each scenario produces four sets of metrics — sender and receiver metrics on both client and server. The scenario name includes the direction:

Metric Name	Unit	Relativity
ThroughputMbps	mbps	Higher is better
TotalBytesMB	MB	Higher is better
AvgBytesPerCompl	B	-
AvgFrameSize	B	-
AvgPacketsPerInterrupt	packets/interrupt	-
InterruptsPerSec	count/sec	-
PacketsRetransmitted	count	Lower is better
Errors	count	Lower is better
CyclesPerByte	cycles/byte	Lower is better
AvgCpuPercentage	%	-
TcpAverageRtt	ms	Lower is better

Telemetry scenario names follow the pattern:

• {Scenario} Client Send — Client's sender metrics (forward direction)
• {Scenario} Client Receive — Client's receiver metrics (reverse direction)
• {Scenario} Server Send — Server's sender metrics (reverse direction)
• {Scenario} Server Receive — Server's receiver metrics (forward direction)