Re: [Bluez-users] Problems connecting to multiple rfcomm sockets

Marcel Holtmann
2004-10-27T15:49:02Z

Hi Steve,

> I've been experiencing some problems when trying to open multiple rfcomm
> ports, with pppd using the rfcomm ports.
>
> I have three bluetooth serial ports setup in rfcomm.conf, but it appears
> that I can open connections to two of them at once.
>
> While the first two serial ports are connected, and the third is trying
> to connect, running rfcomm gives;
>
> rfcomm0: 00:0E:6D:1A:9A:3F channel 1 connected [tty-attached]
> rfcomm1: 00:02:EE:82:D9:29 channel 2 connected [tty-attached]
> rfcomm2: 00:60:57:70:CD:E1 channel 3 config [tty-attached]
>
> Then the terminal with the third connection reports;
>
> "Failed to open /dev/rfcomm2: Host is down"
>
> At which point running #rfcomm gives;
>
> rfcomm0: 00:0E:6D:1A:9A:3F channel 1 connected [tty-attached]
> rfcomm1: 00:02:EE:82:D9:29 channel 2 connected [tty-attached]
> rfcomm2: 00:60:57:70:CD:E1 channel 3 closed.

what does "hcitool con" tell you at this point? Run "hcidump -x" and see
with what error code the third connection fails.

> If I now close the connection to rfcomm1 or rfcomm0, I can connect to
> rfcomm2 (so I can always have a max of 2 active connections).
>
> However, If before I start the pppd connections to the serial ports, I
> start 3 copies of l2ping (one to each of the MAC addresses listed
> above), and keep these running, I can establish pppd connections on
> rfcomm0+1+2 at the same time.
>
> With this scenario, if one of the pppd sessions terminates, the l2ping
> to the corresponding rfcomm device's MAC will stop giving:
> "Send failed: Connection reset by peer", and once again I can only use
> two of the rfcomm ports.
>
> Using bluez-utils-2.10-2 and bluez-libs-2.10-2 under a 2.4.22-1 kernel
>
> Any idea/subjections/requests for more information greatly appreciated!

What devices did you use (hciconfig -a) and to what devices are you
connecting?