AS per above topology,am not able to transfer files with MTU frame size above 1492 though the MTU configured on interface is 1500.The link between DS/PE---CR/PE is mpls enabled i have configured the MTU size to 1524 to carry extra labels of MPLS as recommended by cisco.
When i do extnded ping from DS/PE above MTU size of 1492 with even DF bit not set am not able to ping customer end (B),
AND also i tried with DF bit set am not able to recieve any notifications ICMP destination unreacheable messages.
The file transfer from customer B with packet size above 1492 are received by customer A but when the connection are initiated through customer A they are not.
Within an enterprise it works with larger MTU size when tried to ping from DS loopback to core loopback.How can i troubleshoot it is a problem through my end or from the ISP.
response will be appreciated