PPlay is tool for replaying network traffic from PCAP and SMCAP files.
This site contains video tutorials on the topic - how to replay traffic captures and how to use pplay's features correctly.
You can find the tool at:
www.bitbucket.com/astibal/pplay
... you can also download the tool directly from
bitbucket.org/astibal/pplay/downloads/
You can also have a look at:
www.smithproxy.org
which is my TCP/UDP/TLS transparent proxy software with many features.