Connections that are initiated from the outside will be displayed with a "B" flag. In the output you have given, only two of the connections have the B flag. The rest of them have been initiated from your inside hosts.
That doesn't indicate 0 byte packets - which would be impossible. It does indicate how many bytes have been transferred over that established (or even "un-established" saA) connection. Get used to understanding the direction of your traffic (see link below).
I also recommend you get familiar with syslog - instead of using the cli to analyze connections - as it can be frustrating trying to keep track of those that open and close often and quickly.
Table of ContentsIntroductionVersion HistoryPossible Future
UpdatesDocuments PurposeNAT Operation in ASA 8.3+ SectionsRule Types
Network Object NATTwice NAT / Manual NATRule Types used per SectionNAT
Types used with Twice NAT / Manual NAT and Network Obje...
Table of Contents Introduction:This document describes details on how
NAT-T works. Background: ESP encrypts all critical information,
encapsulating the entire inner TCP/UDP datagram within an ESP header.
ESP is an IP protocol in the same sense that TCP an...