I'd like to ask about QoS Guaranteed Egress, because I'm not sure I understand the topic well. (used devices PA-220 and VM-100)
Here's what I need to do:
My branch office bandwith is limited by the ISP to 30Mbit/sec (ethernet1/1 WAN interface). I need to shape traffic to guarantee some bandwith to different kind of traffic classes, eg. 2 Mbit to class1, 10 Mbit to class2, 10 Mbit to class 3, etc. This is all download traffic, so the egress interface is the internal interface (ethernet1/2, LAN), and I set the QoS profile on this interface.
Bandwith limiting (egress max) is working fine, but guaranteed egress dosen't seem to be working. If, lets say class 4 traffic goes to 30 Mbit/sec, class 1, 2 and 3 becomes slow and can't reach the configured guaranteed bandwith.
Q1. I need to set the configured QoS profile on the egress interface (in this case ethernet1/2), right?
Q2. I read here , that to guaranteed egress to kick in, there has to be congestion on the interface. Since it's a 1 Gbit/sec LAN interface, the egress max is 1000 Mbit/sec. Is this true? Do I need configure egress max (30 Mbit) on ethernet1/2 to create an "artifical bottleneck", to create congestion?
Q3. If I set egress max 30 on ethernet1/2, I limit the download speed of the interface from 1000 to 30 Mbit. That doesn't seem right. What if there are multiple internal interfaces (ethernet1/3 for eg.) and traffic must flow from ethernet1/3 to ethernet1/2 with 1000 Mbit/sec speed (download as well, so egress interface is ethernet1/2 again)?
Q4. You can configure multiple QoS profiles to a physical interface and set source interface. What does source interface means in this case? It's from the perspective of the flow of the packets? In case of download, the traffic egresses the internal interface so source means the ingress (in this case the external) interface? Or it's the interface where the traffic is originating from, where the original SYN packet was sent?
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