mpls vs atm

[carl_townshend]

Hi all, is it true that by converting my isp's core network from atm to mpls they will save 12% overhead ?

[Joseph W. Doherty]

Overhead savings varies based on traffic. You save the "cell tax" (5 bytes of 53), but you also save "cell padding" (e.g. 2 cells, 106 bytes, needed to transmit 49 bytes payload).

[carl_townshend]

can you explain a little mote? what about mpls payload ?