Connection Setup Time

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Connection Setup Time

Connection Setup Time is the time it takes to establish a TCP session between the client and server before data transfer can begin. The network component of this view should be approximately the same as the Effective Round Trip Time.

View the two components of Connection Setup Time separately:

Server Connection Time (SCT) is the time from the initial SYN packet being received from the client until the server sends out the first SYN/ACK.
Network Connection Time (NCT) is the time between the SYN/ACK being sent from the server until the ACK completing the three-way handshake is received.

Look for	Might Indicate
Connection Setup Time is significantly longer than SCT and NCT	Probably caused by server or LAN problems. Compare the Connection Setup Time to the Network Round Trip Time, Retransmissions, and the Server Setup Time to determine whether these views show similar patterns. Typically, Connection Setup Time and Network Round Trip Time increase concurrently though the increase is not linear. Increases in NRTT and Data Transfer Time while Connection Setup Time remains constant might indicate data loss in the direction of client to server. Suspected data loss can be confirmed by the use of a sniffer on the client network to view retransmissions.
Connection Setup Time is significantly longer than SCT and NCT	A spike in the Connection Setup Time correlated with a spike in the Network Round Trip Time indicates that delay is occurring on the network because of an increase in traffic volume and insufficient bandwidth, errors in the network, or an increase in latency caused by a carrier switch to an alternate path. A spike in the Connection Setup Time alone could indicate that the server is stressed because the CPU is overloaded or the TCP/IP session limit is exceeded.

Look for

Might Indicate

Connection Setup Time is significantly longer than SCT and NCT

Probably caused by server or LAN problems.

Compare the Connection Setup Time to the Network Round Trip Time, Retransmissions, and the Server Setup Time to determine whether these views show similar patterns. Typically, Connection Setup Time and Network Round Trip Time increase concurrently though the increase is not linear.
Increases in NRTT and Data Transfer Time while Connection Setup Time remains constant might indicate data loss in the direction of client to server. Suspected data loss can be confirmed by the use of a sniffer on the client network to view retransmissions.

Connection Setup Time is significantly longer than SCT and NCT

A spike in the Connection Setup Time correlated with a spike in the Network Round Trip Time indicates that delay is occurring on the network because of an increase in traffic volume and insufficient bandwidth, errors in the network, or an increase in latency caused by a carrier switch to an alternate path.
A spike in the Connection Setup Time alone could indicate that the server is stressed because the CPU is overloaded or the TCP/IP session limit is exceeded.