[mythtv-users] MythBuntu 11.10 on ESXi

[Gary Buhrmaster]

On Mon, Aug 13, 2012 at 2:59 PM, Joseph Fry <joe at thefrys.com> wrote:
....
> If you have a good swtich, your probably better off aggregating your NIC's
> rather than dedicating on to the HDHR... more overall bandwidth that way.

Yes, and no.  Link aggregation (aka channels, aka bonding) only
*assures* you of a single channel of bandwidth, with the possibility
of greater, with (usually) failover capability.

To avoid being the cause of out of order packets (which, for some
protocols is computationally more expensive, and for other protocols
catastrophic(*)), all properly designed switches default(**) to hashing the
packets from/to the same tuple to the same outbound link.  Depending
on the particular switch, those might include just the destination
MAC, or a combination of source/destination MAC, IP source/dest
values, and port numbers.  But the important point is that all packets
from the same stream go to the same destination port.  So, ideally,
if you have lots of sources, and lots of destinations (and a good hash
implementation), you will get a good hash result, and a good link balance.
In practice, especially in the home environment, you tend to get an
unbalanced use since the overall traffic is much lighter, and at any
one time, only a few source/dests are communicating (unless you are
running a datacenter in your home).  It is all probability and statistics.

Gary

(*) Let us imagine a protocol where the stream order is important,
such as voip, or mpeg transport streams.

(**) Some (usually high end) switches/routers support round-robin
capabilities, but that is rarely the default, since it breaks applications
that presume in-order delivery.