MQTT: receiving large files via MQTT messages on Photon

(For Particle community web page admin: Can we please have a separate MQTT category for the community posts ? Could not figure out a way for me to create it on line… Thank you)

I was wondering anyone has been able to use MQTT to receive messages from IBM IoT for large data sets?

I have been attempting to access IBM Bluemix with MQTT with limited success:

  1. Photon gives up after receiving ~20 MQTT message. I know that the rest of the environment is not an issue because I can do the same with similar eclipse “C” code on my laptop communicating with Bluemix. I.e same wireless LAN + ISP + Bluemix with eclipse code works well in receiving up to 40 KB (Yes Kilo Bytes) broken up into numerous messages , each message carrying 64 byte payload. (see #2 below)

2.There appears to be a MQTT limit of 64 bytes in the payload from my experimentation of receiving MQTT message. I also found on-line in particle reference documents, that there is a call function on photon that limits payload to 63 characters:
-Devices -> call a function ->
-> Function argument with a maximum length of 63 characters
I am not sure this applies to MQTT messages. Can anyone please confirm?

3.Final question: If I use MQTT to access IBM Bluemix, am I going through Particle cloud … even though my photon code has :
a #define MQTT_SERVER ""
I.e. is particle cloud interfering in anyway between photon and Bluemix accesses?

Thanks in advance