Understanding Ingress and Egress Traffic

Cn someone explain what Ingrss and Egress traffic mean.  I understand Ingress means Incoming and Egress means outgoing.  But when I think about it more, it's not as clear.

For example:

I am monitoring traffic in and out form my network.  The switches are all Cisco.  I want to know how much of the packets are being classified, ploced, dropped etc.  I have the upstream router to my service provider connected to my L3 3550.  On the Cisco Network Assistant tool I am using it says

Ingress: incoming
Egress: Outgoing

I have 2 more switches hanging off of my L3 via trunk links.  I am monitoring the traffic at the interface that connects to the ISP.  Therefore, wouldn't it mean that there are 2 Ingress traffic flows:

1. Ingress coming from the ISP (WAN) into the port  to my LAN (what I describe as ingress external or arriving from outside my LAN?
2. Ingress coming from the downstream switches into the port to go out to the WAN (ingress internal originating from  within the LAN to the WAN)?

The same applies with the Egress.

If my description above is correct, how do I distinguish between the Ingress traffic originating from my LAN to the port out to the WAN and vice versa since this is represented by one graph?

in other words, I see these terms as Ingress traffic going out the LAN to WAN and Ingress coming from the WAn to the LAN therefore 4 different traffic buffers vs 2.

Or am I looking into this too much?

Please help be4 my head explodes for no reason.

Thanks


Doc1.docx