Hi Nyasaking,
We also had the same issue when integrating the PRBT service with Intel dialogic cards. each card was supporting 4 E1s. Check with the ISUP trace between the MSC and the dialogic card. The major reason could be due to time difference between the nodes. Due to the difference, the devices are forced to go seal state. finally the card vendor came with some solution.
hope this helps.
xpotentialram@gmail.com
thanks,
ram