linux/include/net/bluetooth
Mat Martineau db12d647cc Bluetooth: Use 3-DH5 payload size for default ERTM max PDU size
The previous value of 672 for L2CAP_DEFAULT_MAX_PDU_SIZE is based on
the default L2CAP MTU.  That default MTU is calculated from the size
of two DH5 packets, minus ACL and L2CAP b-frame header overhead.

ERTM is used with newer basebands that typically support larger 3-DH5
packets, and i-frames and s-frames have more header overhead.  With
clean RF conditions, basebands will typically attempt to use 1021-byte
3-DH5 packets for maximum throughput.  Adjusting for 2 bytes of ACL
headers plus 10 bytes of worst-case L2CAP headers yields 1009 bytes
of payload.

This PDU size imposes less overhead for header bytes and gives the
baseband the option to choose 3-DH5 packets, but is small enough for
ERTM traffic to interleave well with other L2CAP or SCO data.
672-byte payloads do not allow the most efficient over-the-air
packet choice, and cannot achieve maximum throughput over BR/EDR.

Signed-off-by: Mat Martineau <mathewm@codeaurora.org>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
2010-08-10 07:59:11 -04:00
..
bluetooth.h Bluetooth: Use __packed annotation 2010-07-21 10:39:13 -07:00
hci.h Bluetooth: Use __packed annotation 2010-07-21 10:39:13 -07:00
hci_core.h Bluetooth: Use list_head for HCI blacklist head 2010-07-31 16:06:58 -07:00
l2cap.h Bluetooth: Use 3-DH5 payload size for default ERTM max PDU size 2010-08-10 07:59:11 -04:00
rfcomm.h Bluetooth: Use __packed annotation 2010-07-21 10:39:13 -07:00
sco.h Linux-2.6.12-rc2 2005-04-16 15:20:36 -07:00