[Cake] WAN ingress rate with concurrent downloads

[Georgios Amanakis]

Hi Sebastian,

the ISP is Comcast in MD, USA, residential connection. It is a cable
connection (i.e. the WAN port on the modem is a coaxial one) and not a
DSL one. Maximum ingress rate is ~450kbytes/s which is what the modem
syncs at. By using "test_WAN_dual-isolate__piece_of_cake.qos", "tc -d
qdisc show" reports (enp0s13 is WAN, enp0s14 is LAN):
-------8<--------
qdisc noqueue 0: dev lo root refcnt 2 
qdisc fq_codel 0: dev enp0s14 root refcnt 2 limit 10240p flows 1024 		
quantum 1514 target 5.0ms interval 100.0ms ecn 
qdisc cake 8002: dev enp0s13 root refcnt 2 bandwidth 900Kbit besteffort
		dual-srchost nat rtt 100.0ms raw 
qdisc ingress ffff: dev enp0s13 parent ffff:fff1 ---------------- 
qdisc fq_codel 0: dev ifb0 root refcnt 2 limit 10240p flows 1024 		
quantum 1514 target 5.0ms interval 100.0ms ecn 
qdisc cake 8003: dev ifb4enp0s13 root refcnt 2 bandwidth 3300Kbit 		
besteffort dual-dsthost nat rtt 100.0ms raw 
-------8<--------

If one of the hosts on LAN is running bittorrent, bmon on the gateway
reports:
		RX bps 		RXpps	TX bps		TXpps
enp0s14		23.55KiB	303	402.87KiB	322
enp0s13		457.26KiB	369	25.04KiB	307


Setting the ingress rate at 1900kbps (instead of 3300kbps as above),
"tc -d qdisc show" reports:
-------8<--------
qdisc noqueue 0: dev lo root refcnt 2 
qdisc fq_codel 0: dev enp0s14 root refcnt 2 limit 10240p flows 1024 		
quantum 1514 target 5.0ms interval 100.0ms ecn 
qdisc cake 8008: dev enp0s13 root refcnt 2 bandwidth 900Kbit besteffort
		dual-srchost nat rtt 100.0ms raw 
qdisc ingress ffff: dev enp0s13 parent ffff:fff1 ---------------- 
qdisc fq_codel 0: dev ifb0 root refcnt 2 limit 10240p flows 1024 		
quantum 1514 target 5.0ms interval 100.0ms ecn 
qdisc cake 8009: dev ifb4enp0s13 root refcnt 2 bandwidth 1900Kbit 		
besteffort dual-dsthost nat rtt 100.0ms raw 
-------8<--------

Using bittorrent, bmon on the gateway reports:
		RX bps 		RXpps	TX bps		
TXpps
enp0s14		19.25KiB	219	232.51KiB	184
enp0s13		393.36KiB	304	20.25KiB	220

In both cases the ingress rate limit on the WAN interface (enp0s13) is
not obeyed. I verified these data by using tcpdump and doing an IO-
Graph with wireshark.

Looking forward to your feedback,
George