philhartung / node-ptpv2 Goto Github PK

Hi and thanks for open sourcing node-ptpv2.

I have a machine with two network interfaces, en0 and en1, both of which do multicast. There is a PTP grandmaster on a separate machine in en1's network.

$ ifconfig
en0: flags=4163<UP,BROADCAST,RUNNING,MULTICAST>  mtu 1500
        inet 192.168.1.126  netmask 255.255.0.0  broadcast 192.168.255.255

lo: flags=73<UP,LOOPBACK,RUNNING>  mtu 65536
        inet 127.0.0.1  netmask 255.0.0.0

en1: flags=4163<UP,BROADCAST,RUNNING,MULTICAST>  mtu 2800
        inet 172.24.1.126  netmask 255.255.0.0  broadcast 172.24.255.255

When init()ing with en1's address, grandmaster's messages come in fine because the addr is passed through to the addMembership call.

//event msg client
ptpClientEvent.on('listening', function() {
	ptpClientEvent.addMembership(ptpMulticastAddrs[ptp_domain], addr);
                                                                    // ^ explicitly specified
});

However, sending delay_reqs goes over en0 instead, so a sync is never established. I'm wondering if the default interface and routing table should be bypassed, as they are for receiving? Currently, the routing table has to be adjusted accordingly instead. IMO both approaches have their merits, but if it should be up to the routing table I think addMemberships should be called without the addr as well, as that's an optional parameter. Another alternative would be varying what happens based on whether the user explicitly provided the address in the first place, or not.

It's a small change to align sends with the current behaviour for receives, so I'll be sending a PR for that shortly.