/usr/share/freeradius/dictionary.jradius is in freeradius-common 2.1.12+dfsg-1.2ubuntu8.2.
This file is owned by root:root, with mode 0o644.
The actual contents of the file can be viewed below.
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18  | # -*- text -*-
##############################################################################
#
#	jradius VSAs.  See http://jradius.org
#
#	$Id$
#
##############################################################################
VENDOR		JRadius				19211
BEGIN-VENDOR	JRadius
ATTRIBUTE	JRadius-Request-Id			1	string
ATTRIBUTE	JRadius-Session-Id			2	string
ATTRIBUTE	JRadius-Proxy-Client			3	octets
END-VENDOR	JRadius
 |