diff --git a/libs/freetdm/src/ftmod/ftmod_sangoma_ss7/ftmod_sangoma_ss7_main.h b/libs/freetdm/src/ftmod/ftmod_sangoma_ss7/ftmod_sangoma_ss7_main.h
index f88202b1a8..11ff2318bb 100644
--- a/libs/freetdm/src/ftmod/ftmod_sangoma_ss7/ftmod_sangoma_ss7_main.h
+++ b/libs/freetdm/src/ftmod/ftmod_sangoma_ss7/ftmod_sangoma_ss7_main.h
@@ -60,6 +60,10 @@
 
 #define MAX_SIZEOF_SUBADDR_IE	24	/* as per Q931 4.5.9 */
 
+#define SNGSS7_SWITCHTYPE_ANSI(switchtype)	(switchtype == LSI_SW_ANS88) || \
+											(switchtype == LSI_SW_ANS92) || \
+											(switchtype == LSI_SW_ANS95)
+
 typedef struct ftdm2trillium
 {
 	uint8_t ftdm_val;
diff --git a/libs/freetdm/src/ftmod/ftmod_sangoma_ss7/ftmod_sangoma_ss7_out.c b/libs/freetdm/src/ftmod/ftmod_sangoma_ss7/ftmod_sangoma_ss7_out.c
index 91b8900fef..47249c2f5a 100644
--- a/libs/freetdm/src/ftmod/ftmod_sangoma_ss7/ftmod_sangoma_ss7_out.c
+++ b/libs/freetdm/src/ftmod/ftmod_sangoma_ss7/ftmod_sangoma_ss7_out.c
@@ -92,8 +92,10 @@ void ft_to_sngss7_iam (ftdm_channel_t * ftdmchan)
 		/* Transmission medium requirements */
 		copy_txMedReq_to_sngss7(ftdmchan, &iam.txMedReq);
 
-		/* User Service Info A */
-		copy_usrServInfoA_to_sngss7(ftdmchan, &iam.usrServInfoA);
+		if (SNGSS7_SWITCHTYPE_ANSI(g_ftdm_sngss7_data.cfg.isupCkt[sngss7_info->circuit->id].switchType)) {
+			/* User Service Info A */
+			copy_usrServInfoA_to_sngss7(ftdmchan, &iam.usrServInfoA);
+		}
 		
 		/* Called Number information */
 		copy_cdPtyNum_to_sngss7(ftdmchan, &iam.cdPtyNum);