Dear all,

I have a strange issue I am scratching my head over. I wonder if someone could offer any pointers.

I have a Siemen's A580i base and cordless handset connected to my Draytek 2820Vn router. (This is bypassing the internal VoIP settings and just using the Internet Connections).

I have had, for some time, VERY slow call set-up. When I press the green button after tapping in the number, it seems to struggle for up-to 30 seconds before it starts to ring. However, replace the Draytek with a Thompson or NetGear Router and the call set-up is blisteringly fast - as soon as you press the green button you are ringing. Each time, every time.

What on earth with the Draytek would cause the outgoing call set-up to be heavily delayed but a cheaper Thompson or NetGear dials out in seconds?

Brad

don't know that particular device; is it just a normal PSTN telephone, plugged into one of the Phone1/2 sockets?

If so, then the delay is most likely due to the 2820 not switching into bypass properly; there's been a lot of posts here about that. Wonder if it's fixed/better in the new f/w version.

Nope, this is just a VoIP device which plug into one of the 100Mb Network ports on the Draytek via a CAT5 cable.

As much as the Siemens device is pretty poor, when used in the same fashion with the Netgear or Thompson Routers, the call set-up and ringing is instantaneous. To me, it just feels like the Draytek is struggling for some reason before finally letting the call get set-up.

I just cant work out what could cause the delay which is related to the Draytk router but not the Thompson or Netgear. The calls are certianly OK once established.

Any further ideas?

OK; sorry. I googled it after (1) replying and (2) drinking some coffee... then I was thinking straight-er.

I'm guessing here, but - perhaps the 2820 is allowing your outgoing SIP request, but trying to handle the incoming response. It then realises that it can't (VoIP undefined) and THEN hands it to NAT to pass to the ethernet interface/s.

Do you have any VoIP setup in the 2820? And I guess you don't have any port forwarding setup for the Siemens device?

Don't suppose you can run Wireshark? .. then look at the timestamps between data. That should show where the delays are occurring.

I think you may be onto something there. For example, there has been occasions where I think the call has not connected BUT the other side have picked up. In short, the call has been 'set-up' and reached the destination BUT I cannot hear them. When this happens, I sometimes connect and hear them just in time to say 'hello' a second time.

So, maybe calls are getting set-up and (as you say) the router is not allowing the traffic back in for that device for a delayed period - until it hands it back over to the eth port. (This is still strange as my Grandstream GXP2020 is just connected in the same way and this never happens to that!).

With this new revelation in mind - what do you suppose the next thing I should check is?

.. it works for the Grandstream box?? oh, that's weird.

I would have thought it would be the same for both. Maybe there's a difference in SIP timer values used by the GS Vs Siemens unit.

The simple solution as you realised is to use another IP address (via WAN aliasing / address mapping), or NAT all the relevant ports...