To add to Niall's information, here are some other ways you can find this information about how long a Web Service call takes:
1) Use Traffic Monitor. This is available by default by pointing a browser to 8090 on the Gateway. It shows in milliseconds how long each processing step at the Gateway takes, including calls to external Web Services or APIs.
2) Use SR . In the example below, I am using the SR tool (which comes with the free SOAPbox download) to call a Google search API over SSL. You can see it tells me the time the request took. If I want to send many requests, I can do that with the -c (count) and -p (parallel threads) parameters.
C:\soapbox\sr>sr -C -h www.google.com -s 443 -u "/search?as_q=vordel" -v GET -V 1.1 -qq will use HTTPS sessions remote host = www.google.com service=443 URI = "/search?as_q=vordel" verb = "GET" HTTP client version 1.1 quiet quiet 2210 ranges from 0 to 3653.903699 add header Connection: close add header Content-Length: 0 1 threads started time taken: 0.374000 secs. bytes sent: 0.000071MB (ju octets) bytes received: 0.051882MB (ju octets) transactions: 1 connections: 1 sslConnections: 1 sslSessionsReused: 0 bytes sent/sec: 0.000189MB (197.860963 octets) bytes received/sec: 0.138721MB (145459.893048 octets) transactions/sec: 2.673797 protocol/connection errors: 0 transactions by HTTP response code: code=200, count=1