diff --git a/openbsc/doc/sgsn-remote-protocol.txt b/openbsc/doc/sgsn-remote-protocol.txt
index 7ca9094..6564471 100644
--- a/openbsc/doc/sgsn-remote-protocol.txt
+++ b/openbsc/doc/sgsn-remote-protocol.txt
@@ -21,6 +21,12 @@
 messages to/from real MAP messages that can be used to directly communicate
 with an HLR.
 
+2.1. Using IPA
+
+By default, the following identifiers should be used:
+  - IPA protocol: 0xee (OSMO)
+  - IPA OSMO protocol extension: 0x05
+
 2. Procedures
 
 2.1. Authentication management