Vít Lapka - 2022-09-29

Hello,
I have been testing UFTP with TFMCC on low latency link (RTT ~ 27ms) with severely limited maximal rate (down to 1Kb/s): -C "tfmcc:init=1:max=1". However, during the transfer of test file the rate climbed above the limit.
This is caused by order of conditions in function server_transfer.c:handle_tfmcc_ack_info() that updates the rate based on CC_ACK data:

  • max_rate is checked and enfoced
  • min_rate is checked and enforced
  • minimal rate of 1 packet per RTT is enforced

The last condition may violate the configured maximal rate. I have prepared and tested the patch with reordered conditions (see the attachment).
With regards
Vit Lapka

 
03_uftp-5.0.1_tfmcc_maxrate.patch