Go to the domain controller and there is a snaping to manage Distributive file share replication. Check the namespace to see how the replication set is configured.
The delay between sites could be a networking problem with MTU settings, and not necessarily bandwidth. MTU stands for Maximum transmission unit. I like to call it maximum transferable unit. By default Windows domains use a 1500 MTU size. But creating a VPN tunnel between sites or any other Point to Point Protocol (PPP), can add to the payload. So, your tunneling routes could have an exessive payload on the packet that causes problems going through the tunnel. Let's say you have a 1500 byte packet and you add 24 bytes for tunneling through the adapter. That's a 1524 byte packet. In adding to the payload, you exceded your segement size, (this is called Maximum Segement Size Exceded or MSS exceded).
With an MSS exceded problem, you could do one of a couple things. You can increase the MTU size settings on the tunelling routers, and make sure your service providers can support the larger packets. That can be combersome to coordinate this with the ISP.
Or you can enable ICMP. ICMP will allow your packets to divide up into two packets, instead of one. (this is called packet fragmentation).
For more on MTU, MSS exceded, ICMP renegotiation of the packets and packet fragmentation, this is a great article.
http://www.cisco.com/en/US/tech/tk827/tk369/technologies_white_paper09186a00800d6979.shtml
