It has been determined that previous versions of Asterisk used the wrong codeword packing order for G726-32 data. This version supports both available packing orders, and can transcode between them. It also now selects the proper order when negotiating with a SIP peer based on the codec name supplied in the SDP. However, there are existing devices that improperly request one order and then use another; Sipura and Grandstream ATAs are known to do this, and there may be others.
To be able to continue to use these devices with this version of Asterisk and the G726-32 codec, a configuration parameter called 'g726nonstandard' has been added to sip.conf, so that Asterisk can use the packing order expected by the device (even though it requested a different order). In addition, the internal format number for G726-32 has been changed, and the old number is now assigned to AAL2-G726-32. The result of this is that this version of Asterisk will be able to interoperate over IAX2 with older versions of Asterisk, as long as this version is told to allow 'g726aal2' instead of 'g726' as the codec for the call.
