add reference url.

git-svn-id: http://svn.openzap.org/svn/openzap/trunk@214 a93c3328-9c30-0410-af19-c9cd2b2d52af

diff --git a/libs/freetdm/src/dsp/fsk.h b/libs/freetdm/src/dsp/fsk.h
index 0f800bdc125ec7607eaed715bb6437495a2e7062..e6ca995d578690c463a90228c09f22130add5344 100644 (file)
--- a/libs/freetdm/src/dsp/fsk.h
+++ b/libs/freetdm/src/dsp/fsk.h
@@ -42,6 +42,7 @@ typedef struct {
 } fsk_modem_definition_t;
 
 /* Must be kept in sync with fsk_modem_definitions array in fsk.c      */
+/* V.23 definitions: http://www.itu.int/rec/recommendation.asp?type=folders&lang=e&parent=T-REC-V.23 */
 typedef enum {
     FSK_V23_FORWARD_MODE1 = 0, /* Maximum 600 bps for long haul        */
     FSK_V23_FORWARD_MODE2,             /* Standard 1200 bps V.23                       */