Grandstream 1 Port E1/T1 Gateway GXW4501Software configurable E1 T1 J1 ports, support PRI, SS7, MFC R2 Dual Gigabit auto sensing RJ45 network ports with integrated NAT router Supports a wide range of voice codecs, including Opus, G. 722, G. 729, iLBC, and more TLS and SRTP security encryption technology to protect calls and accounts Automated provisioning by HTTP TFTP with XML config files Supports T. 38 Fax for creating Fax over IP Supports multi language voice prompts The GXW4500 series