[Blink] no audio if multiple ip-addresses are active

Kenny MacDermid kenny.macdermid at gmail.com
Fri Aug 13 15:00:01 CEST 2010

On 11 August 2010 04:29, Saúl Ibarra Corretgé <saul at ag-projects.com> wrote:
> Hi,
>> Here's the differences I see between a working SIP/SDP connection with
>> another client, and Blink:
>> My vlan IP is, other IPs on interfaces are and
>> X: Via: SIP/2.0/UDP
>> B: Via: SIP/2.0/UDP
>> -- this is the first case of the wrong IP address. is
>> actually the IP of a vmware interface that's not used for any normal
>> traffic.
> This is not right. Can you reproduce it always? If so, can you give me more
> details on your network setup so I can reproduce it?

I can, it happens with every call I make. My network setup is as follows:

en0: ethernet cable unplugged
en1: wifi IP of
vmnet1: vmware fusion virtual iface, IP
vmnet8: vmware fusion virtual iface, IP
jnc0: vpn interface, IP

My SIP server is at

Routing info (related to the call):

Destination        Gateway    Flags   Netif
default      UGSc   en1
10.1/16     UGSc   jnc0
192.168.53         link#8        UC       vmnet1

The VPN is setup using Juniper Network Connect.

>> X: Contact:<sip:432 at;transport=udp>
>> B: Contact:<sip:tjrkpxia at>
>> -- this is the second incorrect address. is the IP of the
>> default route interface. Also 432 is the extension of the client. I'm
>> not sure what tjrkpxia is.
> Blink currently sends all traffic through the default route, so this is
> expected. If your default route gos through that IP address, it will be the
> one chosen. There is no support for selecting other interfaces.

You say this is expected. Do you mean it's expected currently, but a
bug? The SIP traffic is not being sent out the default route, it's
being sent out the interface (as I would expect). If it's
using an IP for a route it's not using I'd consider that a bug.

>> Now in SDP:
>> X: o=- 8 2 IN IP4
>> B: o=- 3490461286 3490461286 IN IP4
>> X: c=IN IP4
>> B: c=IN IP4
>> the a= lines also differ, but I doubt they'd matter.
> Even if o and a lines are wrong audio would flow if c line is correct. It
> looks like here we have the same case as in the Contact header: the IP for
> the default route is being used, as expected.

Again, not quite sure what you mean by expected.

If I can provide any more assistance on tracking this down let me
know. I'd much rather use Blink than X-Lite.


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