Hi,
We're trying to implement QoS on a WAN-link in our network, but it doesn't work as we expect. De BW of the normal traffic has a maximum of +- 7.1 Mbps while the line is +- 9.8 Mbps. Can somebody explain this to me?
Our configuration:
|Campus Network - Switch A (3560G)|=====+- 10Mbps Leased Line=====|Remote Network - Switch B (3560G)|
We see problems when users on the remote network are using more bandwidth than available by the leased line => traffic is limited to +- 7.1 Mbps for normal traffic (DSCP 0, COS 0) and sometimes our phones (Alcatel) reboot (DSCP46, COS5). I also see traffic with DSCP48, COS6 en COS7. I think that is also VoIP-traffic, but I'm not sure. I have to investigate that.
My questions:
- Why +- 7.1 Mbps? I can't match it with the share and shape values (even when I don't count the weight of queue 1 (priority-queue out)).
- How can I calculate the real bandwidth with share and shape?
Share: BW Queue4 = 20/(10+10+60+20) * BW = 20% * BW => Is it:
1) 20% * 9.8 Mbps (real maximum BW)
2) 20% * 10 Mbps (speed 10 interface setting)
3) 20% * 100 Mbps (mls int queueing operational BW) or
4) 20% * 1 Gbps (max interface speed)?
Same questions with shaping:
BW Queue 3 = 1/100 * BW (which BW?)
When Phone control traffic would be DSCP48 = Queue 2 => Shaped BW Queue2 = 1/100 * BW => 100 kbps (?) should be enough for VoIP control traffic for 4 phones. Why do our phones reboot when normal traffic (queue 4) is at it's limit?
- When I have priority-queue out enabled on the interface, I understand that queue 1 is always serviced when it has packets and share & shape weights of that queue are not taken into account.
Does it mean that in our case, with a WAN-link with a lower BW, these Queue1(VoIP)-packets are always sent first and then the other traffic? => so that we have to make sure all VoIP-traffic use the priority queue 1 and other traffic queue 4 (f.e.) so that shaping & sharing weights are not necessary to give priority for voice traffic?
Interface Switch A:
interface GigabitEthernet0/23
switchport access vlan 200
switchport mode access
switchport nonegotiate
speed 10
srr-queue bandwidth share 10 10 60 20
srr-queue bandwidth shape 5 20 100 0
queue-set 2
priority-queue out
mls qos trust dscp
storm-control broadcast level 5.00
storm-control action trap
end
Interface Switch B:
interface GigabitEthernet0/24
switchport access vlan 200
switchport mode access
duplex full
srr-queue bandwidth share 10 10 60 20
srr-queue bandwidth shape 5 20 100 0
queue-set 2
priority-queue out
mls qos trust dscp
no mdix auto
storm-control broadcast level 5.00
storm-control action trap
end
Qos config on Switch A and B:
mls qos map cos-dscp 0 8 16 24 32 46 48 56
mls qos srr-queue input bandwidth 90 10
mls qos srr-queue input threshold 1 8 16
mls qos srr-queue input threshold 2 34 66
mls qos srr-queue input buffers 67 33
mls qos srr-queue input cos-map queue 1 threshold 2 1
mls qos srr-queue input cos-map queue 1 threshold 3 0
mls qos srr-queue input cos-map queue 2 threshold 1 2
mls qos srr-queue input cos-map queue 2 threshold 2 4 6 7
mls qos srr-queue input cos-map queue 2 threshold 3 3 5
mls qos srr-queue input dscp-map queue 1 threshold 2 9 10 11 12 13 14 15
mls qos srr-queue input dscp-map queue 1 threshold 3 0 1 2 3 4 5 6 7
mls qos srr-queue input dscp-map queue 1 threshold 3 32
mls qos srr-queue input dscp-map queue 2 threshold 1 16 17 18 19 20 21 22 23
mls qos srr-queue input dscp-map queue 2 threshold 2 33 34 35 36 37 38 39 48
mls qos srr-queue input dscp-map queue 2 threshold 2 49 50 51 52 53 54 55 56
mls qos srr-queue input dscp-map queue 2 threshold 2 57 58 59 60 61 62 63
mls qos srr-queue input dscp-map queue 2 threshold 3 24 25 26 27 28 29 30 31
mls qos srr-queue input dscp-map queue 2 threshold 3 40 41 42 43 44 45 46 47
mls qos srr-queue output cos-map queue 1 threshold 3 5
mls qos srr-queue output cos-map queue 2 threshold 3 3 6 7
mls qos srr-queue output cos-map queue 3 threshold 3 2 4
mls qos srr-queue output cos-map queue 4 threshold 2 1
mls qos srr-queue output cos-map queue 4 threshold 3 0
mls qos srr-queue output dscp-map queue 1 threshold 3 40 41 42 43 44 45 46 47
mls qos srr-queue output dscp-map queue 2 threshold 3 24 25 26 27 28 29 30 31
mls qos srr-queue output dscp-map queue 2 threshold 3 48 49 50 51 52 53 54 55
mls qos srr-queue output dscp-map queue 2 threshold 3 56 57 58 59 60 61 62 63
mls qos srr-queue output dscp-map queue 3 threshold 3 16 17 18 19 20 21 22 23
mls qos srr-queue output dscp-map queue 3 threshold 3 32 33 34 35 36 37 38 39
mls qos srr-queue output dscp-map queue 4 threshold 1 8
mls qos srr-queue output dscp-map queue 4 threshold 2 9 10 11 12 13 14 15
mls qos srr-queue output dscp-map queue 4 threshold 3 0 1 2 3 4 5 6 7
mls qos queue-set output 1 threshold 1 138 138 92 138
mls qos queue-set output 1 threshold 2 138 138 92 400
mls qos queue-set output 1 threshold 3 36 77 100 318
mls qos queue-set output 1 threshold 4 20 50 67 400
mls qos queue-set output 2 threshold 1 149 149 100 149
mls qos queue-set output 2 threshold 2 118 118 100 235
mls qos queue-set output 2 threshold 3 41 68 100 272
mls qos queue-set output 2 threshold 4 42 72 100 242
mls qos queue-set output 1 buffers 10 10 26 54
mls qos queue-set output 2 buffers 16 6 17 61
mls qos
#sh mls qos int Gi0/23 queueing
GigabitEthernet0/23
Egress Priority Queue : enabled
Shaped queue weights (absolute) : 5 20 100 0
Shared queue weights : 10 10 60 20
The port bandwidth limit : 100 (Operational Bandwidth:100.0)
The port is mapped to qset : 2
mls qos int stat Switch A:
dscp: incoming
-------------------------------
0 - 4 : 195973 0 0 0 0
5 - 9 : 0 0 0 0 0
10 - 14 : 0 0 0 0 0
15 - 19 : 0 0 0 0 0
20 - 24 : 0 0 0 0 0
25 - 29 : 0 0 0 0 0
30 - 34 : 0 0 0 0 0
35 - 39 : 0 0 0 0 0
40 - 44 : 0 0 0 0 0
45 - 49 : 0 94337 0 10813 0
50 - 54 : 0 0 0 0 0
55 - 59 : 0 0 0 0 0
60 - 64 : 0 0 0 0
dscp: outgoing
-------------------------------
0 - 4 : 209687 0 0 0 0
5 - 9 : 0 0 0 0 0
10 - 14 : 0 0 0 0 0
15 - 19 : 0 0 0 0 0
20 - 24 : 0 0 0 0 0
25 - 29 : 0 0 0 0 0
30 - 34 : 0 0 0 0 0
35 - 39 : 0 0 0 0 0
40 - 44 : 0 0 0 0 0
45 - 49 : 0 94342 0 0 0
50 - 54 : 0 0 0 0 0
55 - 59 : 0 0 0 0 0
60 - 64 : 0 0 0 0
cos: incoming
-------------------------------
0 - 4 : 302750 0 0 0 0
5 - 7 : 0 0 0
cos: outgoing
-------------------------------
0 - 4 : 209701 0 0 0 0
5 - 7 : 94342 0 2
Thanks,
Stefan
