import 3GPP DIAMETER related definitions from travelping/erggw_aaa

There are some dependencies of TS 29.272 which we can inherit from
https://github.com/travelping/ergw_aaa

The version used was from git commit a5d5a93e2ef87f4168c676ee9a6d8300beb729d8
diff --git a/dia/diameter_3gpp_base.dia b/dia/diameter_3gpp_base.dia
new file mode 100644
index 0000000..67e15af
--- /dev/null
+++ b/dia/diameter_3gpp_base.dia
@@ -0,0 +1,71 @@
+;;
+;; %CopyrightBegin%
+;;
+;; Copyright Travelping GmbH 2015. All Rights Reserved.
+;;
+;; Licensed under the Apache License, Version 2.0 (the "License");
+;; you may not use this file except in compliance with the License.
+;; You may obtain a copy of the License at
+;;
+;;     http://www.apache.org/licenses/LICENSE-2.0
+;;
+;; Unless required by applicable law or agreed to in writing, software
+;; distributed under the License is distributed on an "AS IS" BASIS,
+;; WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+;; See the License for the specific language governing permissions and
+;; limitations under the License.
+;;
+;; %CopyrightEnd%
+;;
+
+;;
+;; Edits:
+;;
+;; - Ipv6   -> IPv6
+;;
+
+@id     0
+@name   diameter_3gpp_base
+@prefix diameter_3gpp
+@vendor 10415 3GPP
+
+;; only attributes required by other applications are defined
+
+@avp_types
+
+   3GPP-IMSI                        1      UTF8String     V
+   3GPP-Charging-Id                 2     OctetString     V
+   3GPP-PDP-Type                    3      Enumerated     V
+   3GPP-CG-Address                  4     OctetString     V
+   3GPP-GPRS-Negotiated-QoS-Profile 5      UTF8String     V
+   3GPP-SGSN-Address                6     OctetString     V
+   3GPP-GGSN-Address                7     OctetString     V
+   3GPP-IMSI-MCC-MNC                8      UTF8String     V
+   3GPP-GGSN-MCC-MNC                9      UTF8String     V
+   3GPP-NSAPI                       10    OctetString     V
+   3GPP-Session-Stop-Indicator      11    OctetString     V
+   3GPP-Selection-Mode              12     UTF8String     V
+   3GPP-Charging-Characteristics    13     UTF8String     V
+   3GPP-CG-IPv6-Address             14    OctetString     V
+   3GPP-SGSN-IPv6-Address           15    OctetString     V
+   3GPP-GGSN-IPv6-Address           16    OctetString     V
+   3GPP-IPv6-DNS-Servers            17    OctetString     V
+   3GPP-SGSN-MCC-MNC                18     UTF8String     V
+   3GPP-IMEISV                      20    OctetString     V
+   3GPP-RAT-Type                    21    OctetString     V
+   3GPP-User-Location-Info          22    OctetString     V
+   3GPP-MS-TimeZone                 23    OctetString     V
+   3GPP-CAMEL-Charging-Info         24    OctetString     V
+   3GPP-Packet-Filter               25    OctetString     V
+   3GPP-Negotiated-DSCP             26    OctetString     V
+   3GPP-Allocate-IP-Type            27    OctetString     V
+   TWAN-Identifier                  29    OctetString     V
+   3GPP-User-Location-Info-Time     30    OctetString     V
+
+@enum 3GPP-PDP-Type
+
+   IPv4                                               0
+   PPP                                                1
+   IPv6                                               2
+   IPv4v6                                             3
+   Non-IP                                             4