In case someone else runs into this and finds this thread. The "output attenuation -6" is the right setting to avoid altering the audio and this would be the loudest setting, anything numerically higher (i.e. -5 through 14) would lower the volume. (you cannot increase the volume that goes to PSTN, at least not using the "output attenuation" command) ... View more

Daniele, Thanks for the quick reply. I am a little confused Referring to this paragraph from the configuration guide, "A system-wide loss plan must be implemented using both the input gain and output attenuation commands. You must consider other equipment (including PBXs) in the system when creating a loss plan. The default value for this command assumes that a standard transmission loss plan is in effect, meaning that there must be an attenuation of –6 dB between phones. Connections are implemented to provide –6 dB of attenuation when the input gain and output attenuation commands are configured with the default value of 0 dB." But If in the above description, attenuation of -6DB means a corresponding configuration of "output attentionation 6" in that case setting output attenuation to -6 fits well, after some thought this seems like the right thing, but wanted to get it clarified. Also the platform we are using is a 2811 which does not have the nextport stuff, is there anything specific to the ISR platforms for fine tuning gain/echo-cancellation issues? Thanks again. ... View more

Alberto, Thanks for the answer, it's been a while but I thought I should update the thread so other people might find it useful. After numerous test we found out that the "Gain" values on the SPA2102 was what made the biggest difference, tweaking and setting them to lower values seems to have resolved most of the issues. ... View more

Thanks! Yes that would work, but we have close to 50 T1's and I am trying to reduce the number of chassis to like 3, as opposed to 6. Now costwise, 2x 2921's ~= 1x 3925, which is certainly doable, but long-term, power usage on 6 chassis vs 3 chassis is going to be a saving, plus a 4th chassis can give the needed spare/redundancy. Converting 50 T1's to two DS3's is outside the scope of approved things on this project While the solutions suggested here are doable and perfectly fine, I am specifically looking to see if the capacity in question is a possibility. ... View more

Thanks! I understand that something in the AS5xxx can be put in place. But the major advantages of the AS5400 is all we don't need here: SS7 support, ability to group multiple gateways together via MLPPP And mainly can't justify the cost of getting a new cisco 3950 with all cards (~$24000) vs the AS5400 series (> $40000). I am just curious if anyone has done this and if not then atleast say that they have seen this configuration working somewhere. The fact that the 3900 series is more recent makes it a little more harder. ... View more

Unfortunately data on this link concerns me. http://www.cisco.com/en/US/prod/collateral/routers/ps10536/Routing_Poster.pdf It says a 2921 can only have 240 Digital Voice channels, which means a maximum of 10 T1s. Althought it can have 400 sip sessions. If what I interpreted is true, then the next logical step is to choose 3925. In that case, I would like to apply my original question to the 3925 router, will it be happy with 16T1's in its stomach? Thanks! ... View more