Topic: VoIp behind SME server/firewall

[tlicht]

Hi,
Having problems with VoipBuster behind an SME server/firewall version 6.5.
The call gets set up all right - at least the phone rings at the other end.... but:
If I don't forward any ports, I can hear the party that I call but the other party cannot hear anything - at least not me .
If I forward the ports suggested on the Voipbuster website (UDP 5060, UDP 11112, UDP 10300 - 10311 and UDP 6901 - 6920) then neither I nor the other party can hear anything .
Anybody has any nice ideas?
Thanx.

[arne]

I use Voipbuster, Skype, Freeworld and a number of other iptelephones with or without adapters behind a SME 7.0 Beta 4 to check out and learn the new telephone technology.

Voipbuster and all the other iptelephones run without a problem behind the SME 7.0 B4 gateway.

Most those I have tested works without any portforwarding. There is actuelly only one that apear to need port forwarding (and this is not Voipbuster.)

I have had quite the excact problem as you describe when I have used some cheap gateway routers (Brand not "sme server" but Belkin and Topcom.)

I have not tested the 6.5 as a gateway, but I wuld guess it should work (like the 7.0 Beta.)

I would rather guess that there is something else than the sme 6.5 that is preventing the comunication.

Is there some other routers or hardware/software firewall involved in the data transport ? (Personal firewall at the Windows work station ?)

If you have the oportunity to this you could try the 7.0 B4. (When I think it over I believe that I saw in some other tread that "somebody else" used sme 6.5 and that this worked as well.)

Best reg Arne.

[tlicht]

Thanx Arne,
I am not at that computer for the moment - it is a friend's - but as far as I recall, no software gizmo of the firewall type is installed on her w2k (not xp) computer. Other than that only the ADSL modem is involved - I use the same kind of ADSL modem at my place and I have no problems with VoipBuster or Skype....
Well, I'll have to try to find some other source of the problem....

[arne]

Hello tlicht !

At my friends apartement it was rather big problems with the sip telephone connection. He used a Topcom adsl modem. It was set up to run in routing mode. Then we reconfigured to run in bridging mode, and set up a new router behind the adsl modem. This was an inexpensive SMC Barricade Broadband Router 4P.

He still use the same Topcom adsl modem, but with other configuration, and there is now zero problem with his sip telephone.

Some "traditional equipment" (typical routers) has problems with the special trafic patern of a sip telephone. I believe that the Sme 7.0 (and Linux 2.6.x) can do it ok.

Best reg Arne.

[tlicht]

Hi Arne,
Both my friend and I have XAVI XX7722r+ modems, but for all I know, they can be differently configured.....
So I'll test to change modems and see if it makes any difference.
Unfortunately I don't have access to the configuration interface to the modem(s) since my ISP (Bredbandsbolaget) keeps the password secret..... They are very good at billing but really poor at delivering broadband internet connection....
Regards
Thomas

[tlicht]

It doesn't seem to be a modem problem....
Tested the friend's modem at my place and everything worked fine.... then again, I use an IPCop firewall.

So I started to check the logs of the SME server and found lines like this:

filialen kernel: denylog:IN=eth1 OUT= MAC=00:0a:cd:0d:f2:5c:00:d0:01:7e:13:fc:08:00 SRC=62.132.0.89 DST=83.227.185.136 LEN=70 TOS=0x00 PREC=0x00 TTL=116 ID=33109 PROTO=UDP SPT=6902 DPT=41681 LEN=50

which is pretty much greek to me, but at least I recognise the MAC address of the SME server's outside network card, eth1 ( 00:0a:cd:0d:f2:5c ). The MAC 00:d0:01:7e:13:fc could possibly be the address of the other end (the gateway side) of the outside connection, since it is one of the addresses returned by the arp command on the SME server. The SRC=62.132.0.89 is not recognised by any DNS server (nslookup) but is hopefully the voipbuster server that is denied to get in.... 83.227.185.136 is naturally my friend's internet address. SPT=6902 might be the UDP port that voipbuster uses.....

Anyway, I tried with and without opening the voipbuster recommended ports - no positive results....

...so I am open for almost any suggestions '