Please help me understand Mikrotik’s definition of “Throughput”
E.g.
Looking at the figures published by Mikrotik for RB2011 at https://mikrotik.com/product/RB2011UiAS-2HnD-IN.
Using the first line of values under Ethernet Test Results as example, then connect a 1Gb connection to pc1 on ether1 and
a 1Gb connection to pc2 on ether2 and start a large file download from pc2 downloading from pc1, will
this mean i will theoretically:
Download at ± 1.4Gbps, 1.4 Gbps coming in on ether1 and 1.4Gbps going out on ether2, or
Download at ± 700Mbps, 700Mbps coming in on ether1 and 700Mbps going out on ether2
If my thinking is correct on your post, why will it not be 1.25Gb as that is the theoretical limit for Gb interface and will be closer to Mikrotik’s published data?
This is because a router can forward more throughput than the maximum data rate of a single port.
Suppose you have a router with 4 gig-e interfaces. You could potentially have up to 4 gigabits of total throughput here.
1->2 @ 1gbps
2->1 @ 1Gbps
3->4 @ 1Gbps
4<-3 @ 1Gbps
Of course there are infinitely many ways to subdivide these streams up, but essentially, the most the router can actively forward would be the combined output bandwidths of its physical interfaces. Since Mikrotik routers are CPU-based routers, they tend to only be capable of forwarding traffic at some maximum capacity which is less than this sum of all interfaces, but they can be capable of forwarding more bandwidth than the speed of any single interface.
The reason my example represents only 4Gbps and not 8 is that the entire trip through the router represents one packet forwarded - ingress : processing : egress. Only 4 distinct data streams are flowing through the router.
