Break a 140MB file to smaller files

edit

even 30MB would be too much for most users because the binary files are being transfered using Base64 encoding which will make your 30MB file like 40MB+ mail - an easy way to fill up user's quota.

Use dropbox/wetransfer etc instead - your recipient will thank you for saving time by avoiding mergecap'ing

This discussion has some different ways:

https://serverfault.com/questions/131872/how-to-split-a-pcap-file-into-a-set-of-smaller-ones

Everyone has their preference, but I prefer:

tcpdump -r old_file -w new_files -C 10

Where C is in MB. Another good discussion on the topic using editcap:

https://blog.packet-foo.com/2018/07/pcap-split-and-merge/