WAN High Bandwidth to Low Bandwidh file transfer

[CHRIS KALETH]

We have an MPLS network with Site A having a 22MB and Site B a 3MB connection to the cloud. If a large ftp is initiated from Site A (5 GB) to Site B will Site B be able to throttle back the file transfer and not congest the WAN interface. Someone did this and Site B went from a 40ms response to a 700ms response. We do have Qos setup just for voice but even then it was very sluggish. Both routers are new Cisco 3825's

[Joseph W. Doherty]

I'm assuming you have other sites connected to your MPLS network beyond sites A and B. I further assume you don't have anything like PVCs across your MPLS network; any site can communicate with any site.

The best way to deal with this situation, not only for high to low, but for multiple sites to one site, is QoS on the MPLS egress link. Normally, you won't have much control beyond marking traffic to work within the provider's QoS model. Mark FTP into a bulk class, and only that class should see a major increase in latency.

PS:

The other direction, low to high, should not only mark to take advantage of the MPLS provider's QoS model, but should implement congestion management for its outbound traffic. FTP again would be managed to not be detrimental to other traffic.

Summary: manage local congestion, mark traffic to manage remote egress congestion.