This is merely a historical archive of years 2008-2021, before the migration to mailman3.
A maintained and still updated list archive can be found at https://lists.osmocom.org/hyperkitty/list/osmocom-net-gprs@lists.osmocom.org/.
Holger Hans Peter Freyther hfreyther at sysmocom.deOn Mon, Nov 25, 2013 at 08:24:27AM +0100, Andreas Eversberg wrote: > could this be an mtu issue at the phone? does the phone requests an > uplink tbf to send a pong? the first 10 pings going through and then nothing coming back? I don't think it is a MTU issue. I don't know what the root cause is but the structure of the code doesn't make it easy to find it. > > In both cases it could be a scheduling issue (e.g. we don't schedule > > the UL Packet ACK/NACK). > in case of an ongoing uplink tbf, we ack/nack received or timed out > uplink rlc/mac blocks by using a control block. even if there is an > ongoing downlink tbf, all control blocks have priority over data blocks. As I have already pointed out. Some control blocks can starve. I don't know if it does but it is where I will continue to have a look. > > Is any of you aware of it? I had already > > highlighted that the scheduling is not fair. I wonder if we are seeing > > starvation (and will re-factor to be able to unit test this). > > > > In terms of scheduling. For the SBA we are already having a reservation > > that we try to honor in multiple places. Maybe it is time to extend it > > and have more reservations? > > > uplink control messages are reserved in the tbf object (poll_fn). the > sba control messages are reserved in a separate structure, since sba are > not (or not yet) related to a tbf. well. In the tbf you have: else if (bts->sba()->find(trx->trx_no, ts, (fn + 13) % 2715648)) LOGP(DRLCMAC, LOGL_DEBUG, "Polling cannot be " "sheduled, because single block alllocation " "already exists\n"); But there is nothing that checks if another TBF is setting poll_fn to a frame that another tbf is already polling. -- - Holger Freyther <hfreyther at sysmocom.de> http://www.sysmocom.de/ ======================================================================= * sysmocom - systems for mobile communications GmbH * Schivelbeiner Str. 5 * 10439 Berlin, Germany * Sitz / Registered office: Berlin, HRB 134158 B * Geschaeftsfuehrer / Managing Directors: Holger Freyther, Harald Welte