u know how data roaming works?

The data either can be routed by
1)  Ur phone ---> roaming partner ---- > internet

2) Ur phone ----> roaming partner ------ > umobile ----> internet
most of the telco using 1) as no trust between operator, which mean every month roaming partner will bill umobile for RMxxxx due to UM user roam to their network.
UM cannot verify as no billing on its own network..

So here comes 2) option,
EVERY BITS of ur data will be route from roaming partner to u mobile via a server/company, BUT, limited bandwidth until today.. PnC cannot tell the bandwidth but u will be shocked AS the trunk is shared by whole roaming partner ... which mean those roaming at every country will send to the same trunk/link and back to umobile

everyone at oversea -----> every roaming partner -----(limited bandwidth) ----> umobile ---> internet

can u imagine the link is even worse than u grab capacity with other ppl within a telco tower?    and u still need to fight with ppl using LTE and U mobile VIP

  cheer up, u really tot umobile will be so nice? unlimited?