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Andreas Eversberg andreas at eversberg.euHolger Hans Peter Freyther wrote: > * there is no indication to the SGSN for dropped frames/octets? > * can't the DL-TBF be re-associated/updated after the assignment > is done again? > hi holger, there is one issue about failed downlink TBF: the PCU does not do any retry. when the assignment is sent to the phone and it fails, there is no retry according to the specs. i assume that this is a task for the SGSN. osmo-sgsn/openggsn does not resend any LLC frame in case of LLC-DISCARDED message, if i look at the source code of libosmogb. (LLC-DISCARDED is forwarded at bssgp_rx_llc_disc() of gprs_bssgp.c, but i don't see where it is handled.) what actually happens is that TCP layer will do the resend, but this is a problem, especially at the border of coverage where many downlink assignments get lost. i have once enabled the debugging at ipaccess BTS and saw that the PCU itself does the retry of lost downlink assignments (4 or 5 times). regards, andreas