laforge has posted comments on this change. ( https://gerrit.osmocom.org/c/libosmocore/+/22343 )
Change subject: gprs_ns2: inform the NS user (BSSGP) about the MTU of a NSE ...................................................................... Patch Set 9: (2 comments) https://gerrit.osmocom.org/c/libosmocore/+/22343/9/src/gb/gprs_ns2_fr.c File src/gb/gprs_ns2_fr.c: https://gerrit.osmocom.org/c/libosmocore/+/22343/9/src/gb/gprs_ns2_fr.c@804 PS9, Line 804: /* 48.016 ยง 6.1.4.2 default maximum information field size of 1600 octets : * FR has 2 byte header */ : bind->mtu = 1600 - 2; I think the "information field" is what comes after the header, so (without checking the specs again) my assumption was that on the wire it is 1600 bytes plus FR header plus CRC plus flag octets. And hence here mtu = 1600. I just checked FRF.1.2 and Q.922 and I think it supports my position here. Nevertheless, the actual device MTU should be read from the net-device once we actually bind to it. I guess you're doing this in a follow-up patch in this series (haven't looked throuhg it yet). https://gerrit.osmocom.org/c/libosmocore/+/22343/9/src/gb/gprs_ns2_frgre.c File src/gb/gprs_ns2_frgre.c: https://gerrit.osmocom.org/c/libosmocore/+/22343/9/src/gb/gprs_ns2_frgre.c@577 PS9, Line 577: bind->mtu = 1600 - 2; same here. Also, probably worth adding a #define in the frame_relay.h file for this? -- To view, visit https://gerrit.osmocom.org/c/libosmocore/+/22343 To unsubscribe, or for help writing mail filters, visit https://gerrit.osmocom.org/settings Gerrit-Project: libosmocore Gerrit-Branch: master Gerrit-Change-Id: I5016b295db6185ec131d83089cf6c806e34ef1b6 Gerrit-Change-Number: 22343 Gerrit-PatchSet: 9 Gerrit-Owner: lynxis lazus <[email protected]> Gerrit-Reviewer: Jenkins Builder Gerrit-Reviewer: daniel <[email protected]> Gerrit-Reviewer: laforge <[email protected]> Gerrit-Comment-Date: Fri, 12 Feb 2021 08:54:33 +0000 Gerrit-HasComments: Yes Gerrit-Has-Labels: No Gerrit-MessageType: comment
