I have got a Cisco AS5300 with 2PRI DFC which i am trying to use as a voice gateway. when I displayed the show version of my device there were no dsp ressources however i was able to configure the 2 ports and even got voice ports created (I know ordinary router won't allow me to do so without DSPs). So does the AS5300 not require DSP? what are the Feature cards with Six PVDM slots good for then?
You need to check the chassis and see if there is another card called the VFC (voice feature card). This card has DSP modules that clip on it and gives the voice capabilities. Have a look here for more details -
The AS5300 does NOT use PVDM DSP modules as used on other Cisco platforms.
You may also find you have a digital modem carrier card and MICA digital modems installed - these look similar to the DSP modules but are not voice (voip) capable.
Also keep in mind the AS5300's are almost 10 years old now and are no longer supported by Cicso :-)