I have a problem of sending large data through WAN link between two cisco routers .The WAN link consists of 6 E1s lines that are aggregated through Multilink PPP (large BW). The connection between two router are done and when tested using with normal ping we get excellent results (no packet drop and fast ping response). When increasing the size till 3000 (everything still workfine). When increasing packet size starting from 4000 till 18000 we get packet loss with random percentage (sometimes 2 packets ,sometimes 4 packet, ofcourse when packet size increase the more packet loss happens).
This of course don't allow us to send large file size through WAN link (i.e. when sending 8MB file through the link. we get the file with percentage of error 4% (data loss) )
Does anyone can help about this issue ?!! and What's the possible causes and how to solvew it?
Thanks in advance