We have intermittent problems on the incoming calls. they sound robotic for the called end. Call flows from PRI -> Nortel System->( here nortel pushes calls to Cisco, we have 4 TIE lines interconnecting Cisco gateway)- > Cisco GW. When ever a calls takes this path we have this issue and this cannot be reproduced. We checked the T1 line both on carrier end and on our end but no errors. We even upgraded flash on Cisco.. no solution..Can anyone help me out in this?