He hecho varios tests en Glasnost. Aquí pongo uno de los resultados, pero sería interesante que otros usuarios hicieran el test, y lo publicaran por aquí, a ver qué sale:
Your ISP appears to rate limit your uploads.
Details:
Your ISP appears to rate limit your HTTP uploads. In our tests, uploads using control flows achieved up to 404 Kbps while uploads using HTTP achieved up to 527 Kbps.
Your ISP appears to rate limit uploads on port 46275. In our tests, uploads on port 8080 achieved up to 392 Kbps while uploads on port 46275 achieved up to 527 Kbps.