Replication over WAN not maxing out Line

[sjutras]

Hi,

I have a setup with 3 ESX, ESX1 and ESX2 on the same LAN and ESX3 on another site, linked via a site-to-site VPN over a T1 (1.5mbit)

THe Veeam B&R station is in a Windows 2003 R2 VM guest running on ESX3 on local storage.
I have a guest named lets say SERVER1 that runs on ESX1.

if i replicate to ESX2, it is a 600MB differential, and very fast, takes about 1minutes for the process to complete.
if i take ESX3 and bring it to main site on the same LAN as ESX1 and ESX2, and replicate SERVER1 to ESX3, it is a 600MB differential, and very fast, takes about 1minutes for the process to complete.

BUT if ESX3 is on the distant site, if i replicate SERVER1 to ESX3, it is a 600MB differential, and very slow and i mean very slow, for the same 600MB differential it can takes about 4 hours, which gives about a performance of 0.3mbit.

But if i simply copy a file over the WAN between a guest running on ESX1 and another guest running on ESX3, i can reach 150KB/s which is 1.2mbit and makes more sens than 0.3mbit.

What could cause Veeam to not be able to use the available bandwith?

Thanks
Seb

[Gostev]

Hello Seb, the issue does not have to deal with Veeam, but rather it is due to the packet fragmentation happening on your VPN connection.
There is an existing topic describing this issue and some workarounds, please continue discussion there.
Problems with making replication work across a WAN/VPN?

I will lock this thread to prevent duplicate discussions. Thanks!