ISP Information:
The control for the level of sound coming out of the left or right speakers. If you turn the balance control all the way in either direction, you can isolate the sound to the left or right channel, which helps in troubleshooting whether both speakers are connected properly. Other than that, the balance control can fine-tune volume levels to compensate for sound conditions in the room. ISP Glossary:
Balance - On 10 Nov 2003 23:39:08 -0800, scngupta@yahoo.com (Sachin Gupta) wrote:~ Aaron Leonard wrote in message news:...~ > The term "Modem over IP" encompasses a multitude of sins.~ >~ > Most commonly this will be just "modem passthrough", which~ > means that the modem tones are simplemindedly carried in a 64k~ > stream (G.711 or G.clear codecs) with echo cancellation and~ > voice activity detection turned off.~ > http://www.cisco.com/univercd/cc/td/doc/product/software/ios121/121newft/121t/121t3/dtmodptr.htm~ >~ > There is also "modem relay", whereby the modem data is demodulated~ > by the DSPs at the edge of the voip network, so that only the data~ > payload needs to be carried thru the IP net. See~ > http://www.cisco.com/univercd/cc/td/doc/product/software/ios122/122newft/122t/122t11/ftmodrly.htm~ > I believe that this is a Cisco-proprietary scheme.~ > The ITU was working on a standard for this ("V.MoIP"),~ > but I haven't heard any news on this lately.~ >~ > Here's a pretty good whitepaper on the top from Mindspeed:~ > http://www.mindspeed.com/web/download/download.jsp?docId=7213&mode=attachment~~ Aaron,~~ Thanks for the links and useful information. The approved standard for~ MoIP is V.150.1 and CISCO's documentation gives no hint of whether it~ is V.150.1 compliant.Wow, I wasn't even aware that V.MoIP had been ratified by the ITU.I've done some research and can state that we do not yet supportV.150.1 modem relay.~ Even for the Modem Passtrhu mode - CISCO doesn't mention whether their~ scheme is standard compliant or not.~~ SachinSure, our modem passthrough implementation is "standard compliant", notthat I'm aware of any standard per se for modem passthrough. I.e.just use G.711 (u-law or a-law) over RTP with your echo cancellers disabled,VAD turned off and static jitter buffers. RTP redundancy if used isgiven in RFC-2198; DTMF is encoded in RTP per RFC-2833.Modem detection is triggered a la E.164 by sensing the V.25 ANSam.Aaron
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