[Users] Re: Re: Re: Re: MediaProxy & PSTN GW

Ozan Blotter cosmocid at ispro.net.tr
Mon Aug 22 12:37:54 CEST 2005

Dear Klaus,

As i get ideas from three people here i should close this subject. Codec i 
use is g729 (it supports g711 too) as it comes default with Zyxel Prestige 
2002, even i have a special firmware (engineered one) for this product so it 
supports g723 too :P, i think problem is high latencies in ADSL or CableNet 
services here, even they're 512/128, 1024/256, 2048/512 in ADSL and 512/256, 
1024/512, 2048/1024 in CableNet...

Anyway i will try to find another solution and thanks for your replies...



Message: 3
Date: Sat, 20 Aug 2005 23:03:59 +0200
From: Klaus Darilion <klaus.mailinglists at pernau.at>
Subject: Re: [Users] Re: Re: MediaProxy & PSTN GW
To: cosmocid at ispro.net.tr
Cc: users at openser.org
Message-ID: <43079ABF.9030405 at pernau.at>
Content-Type: text/plain; charset=us-ascii; format=flowed

That does not help you - inserting another hop can not compensate the
bottleneck between the UAs and the Internet (the ADSL connection).

BTW: 600km is not far away. Which Codec you you use? Try low-babdwidth
codecs like G729, ilbc, GSM and G723


Ozan Blotter wrote:
> Dear Iqbal and Bogdan,
> That is exactly what i need to improve QoS, because the UAs ADSL
> connection is not fast enough, 512/128k in general, OpenSER and UA's are
> located in same city but PSTN GW is nearly 600 km (350 miles nearly) away
> from this point. I thought since OpenSER is on a good connection (1Mbit
> Fiber) and can relay to PSTN faster then UA's themselves.
> Thanks,
> Ozan
> Also in terms of ping times how far is the PSTN gateway, as Bogdan said,
> media proxy will add even more delay, as for sending pstn via
> mediaproxy, you could do all yourprocessing, and once ser detects that
> call must goto PSTN, then do all the NAT checking ...this is a
> oversimplified view...
> Iqbal
> Bogdan-Andrei Iancu wrote:
>>Hi Ozan,
>>so, if I get it right, you have a PSTN gw locate far away from the
>>UAs...and instead of letting the media traffic to do directly between
>>GW and UAs, you want to insert in the middle a RTP relay (mediaproxy)
>>in order to improve the QoS, right?
>>If so, I would say this will not help you -  having a media relay on
>>your media path leads to QoS degradation due additional delays....
>>If you still want to go for it....I will take a look on tour script.
>>Ozan Blotter wrote:
>>>Dear List,
>>>At below config. i setted up OpenSER on Public IP and PSTN Gateway is
>>>again on another Public IP. I use Zyxel Prestige Series 660-HW ADSL
>>>modems on both client side and note that they have SIP ALG, also i've
>>>completed port forwarding in each modem, so SIP2SIP call happens
>>>(voice traffic goes from UA to UA) without need of anything extra as
>>>STUN or RTP RELAY. But since those are very away from each other if a
>>>UA needs to call PSTN the voice traffic flows from UA to PSTN and
>>>that lowers QoS :(
>>>I would like to activate MediaProxy again but just for one case which
>>>is PSTN, so whenever a UA needs to call PSTN the voice traffic flows
>>>like :
>>>UA (ATA) >>> OpenSER + MediaProxy >>> PSTN
>>>How can i setup this like above without touching SIP2SIP calls
>>>between UA's...
>>>or adding the lines beginning with # these to my existing config is
>>>enough ?
>>>Ozan Blotter 

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