We have a AS5300 connected by port LAN to our network IP and by a port E1/PRI (0:D) connected to a central telephone office Lg-ldk300, which as well has a port ISDN PRI connected to the public network of telephony:
(PSTN -- >lg-ldk300 -- >as5300 -- >ip NETWORK)
We wished to know what considerations we must have as much in the configuration of the Cisco for port E1/PRI, like for the serial interface, since we want to be able to make calls from our network IP towards external numbers, happening to through of the Central telephone office Lg-ldk300.