On 10/13/21 11:29 AM, Adam Thompson wrote:
I've got a downstream customer asking for help; they have a private
internal network that I've taken to calling the "partial-mesh network
from hell": it's got two partially-overlapping radio networks, mixed
with islands of isolated fiber connectivity.
Dynamic routing protocols (IS-IS, OSPF, EIGRP, etc.) generally will
only select the _best_ path, they won't spread the load unless all
paths are equal - and they are very unequal in this network, ECMP
would likely fail horribly.
The network is becoming bandwidth-limited, so they're wanting to make
use of all available paths, not just the single "best" path. It's
also remote and spread out, so adding new links or upgrading existing
links is difficult and expensive.
Oh, and their routers are overdue for a refresh, so acquiring
replacement h/w is now possible.
Has anyone come across any product or technology that can handle the
multi-path-ness and the private-network-ness like a regular router,
but also provides the intelligent per-flow path steering based on e.g.
latency, like an SD-WAN device (and/or some firewalls)?
Maybe add a little bit of linear optimization on top of
faucet/openvswitch/openflow to calculate best paths based upon
bandwidth, paths, and fill-factors. There is a presentation where
Google uses that technique to obtain high utilization on their links
(not necessarily those tools though).
Raymond Burkholder
