Large packet captures, with little corroborating information like a time or ephemeral port of interest, can be annoying to work with. One old trick is to add a column that shows "http.time" which allows you to quickly look at the quickest and slowest TTFB transactions. One shortcoming to this sort is that it doesn't show you data for requests that had no HTTP response captured. This can either be due to a prolonged hang, or bad luck at the end of a capture. To check for these directly, you can filter on ""http.request && !http.response_in" which will show you requests that never got a response (http.response_in is used internally by the dissector when piecing together http.time values)