[ovs-discuss] What determines bridge's max capacity

[Jesse Gross]

On Thu, Dec 12, 2013 at 3:19 AM, the mad <themadengin33r at gmail.com> wrote:
> Hi i am new to ovs,
> trying to understand what determine bridges Maximum capacity.
>
> created bridge and connected two vifs
> ovs-vsctl add-br dhcp
> ovs-vsctl add-port dhcp vnet0
> ovs-vsctl add-port dhcp vnet1
>
> ovs-ofctl show dhcp
> OFPT_FEATURES_REPLY (xid=0x2): dpid:000002b7ecaae144
> n_tables:254, n_buffers:256
> capabilities: FLOW_STATS TABLE_STATS PORT_STATS QUEUE_STATS ARP_MATCH_IP
> actions: OUTPUT SET_VLAN_VID SET_VLAN_PCP STRIP_VLAN SET_DL_SRC SET_DL_DST
> SET_NW_SRC SET_NW_DST SET_NW_TOS SET_TP_SRC SET_TP_DST ENQUEUE
>  13(vnet0): addr:fe:54:00:50:e7:e5
>      config:     0
>      state:      0
>      current:    10MB-FD COPPER
>      speed: 10 Mbps now, 0 Mbps max
>  14(vnet1): addr:fe:54:00:d1:7b:e0
>      config:     0
>      state:      0
>      current:    10MB-FD COPPER
>      speed: 10 Mbps now, 0 Mbps max
>  LOCAL(dhcp): addr:02:b7:ec:aa:e1:44
>      config:     0
>      state:      0
>      speed: 0 Mbps now, 0 Mbps max
> OFPT_GET_CONFIG_REPLY (xid=0x4): frags=normal miss_send_len=0

These numbers are just placeholders, they don't correspond to any actual speed.

> I dont know whether i am understanding it correctly ovs-ofctl show dhcp
> shows 10 MBps,but iperf between two vms show  672 Megabytes.
>
> Why would there is difference between announced and actual capacity.
> also is it possible to create isolated bridge with higher capacity.

The speed of the CPU determines the actual rate that traffic is forwarded.