I have a 7206VXR/NPE400 with a PA-MC-8T1 installed. I also have a T3 card in it for other connectivity.
I have 4 of the T1 ports used. 2 of those are in a Multilink PPP configuration to form one 3Mbps connection.
On the other side of the connection, I have a 2801 with 2 WIC-1DSU-T1-V2 modules in it.
The customer is complaining of slowness, and the bandwidth graphs from my NMS show that the Multilink interface isn't hitting 100% at any time.
So, I'm doing some bandwidth testing with an FTP site. I've move all other traffic off of the Multilink connection and I'm downloading/uploading a large file from an FTP site to one client plugged directly into the router.
The results are interesting. Traffic from the 2801 side, destined for the FTP server behind the 7206, reaches the full 3Mbps just fine. However, traffic in the other direction, from the FTP server behind the 7206 destined to the FTP client behind the 2801, only reaches about 1.8Mbps total.
I've taken each T1 down and run the test on either of them alone, and they both perform at full 1.5Mbps on their own. I've also torn down the Multilink PPP configuration and had then be simply HDLC with IP addresses, and they do 1.5Mbps on their own as well. I've also tried using 'ip load-sharing per-packet' instead of MLPPP, and that configuration only gets me to 1.6Mbps.
There are no errors on the T1s or any of the Ethernet ports along the way. I do FTP through this router's T3 interface to the same FTP site and it reaches 45Mbps just fine, so the FTP site/server isn't the issue.
CPU doesn't seem to be high (5-6%), and the memory on the router seems fine.
Any ideas from anybody? Has anyone actually used a PA-MC-8T1 to do Multilink PPP?