diff --git a/src/csn1.cpp b/src/csn1.cpp
index 54cc411..82bf17f 100644
--- a/src/csn1.cpp
+++ b/src/csn1.cpp
@@ -2400,7 +2400,12 @@ gint16 csnStreamEncoder(csnStream_t* ar, const CSN_DESCR* pDescr, bitvec *vector
             guint8 bits_to_handle = remaining_bits_len%8;
             if (bits_to_handle > 0)
             {
-              guint8 fl = filler&(0xff>>(8-bits_to_handle));
+              /* section 11 of 44.060
+               * The padding bits may be the 'null' string. Otherwise, the
+               * padding bits starts with bit '0', followed by 'spare padding'
+               * < padding bits > ::= { null | 0 < spare padding > ! < Ignore : 1 bit** = < no string > > } ;
+              */
+              guint8 fl = filler&(0xff>>(8-bits_to_handle + 1));
               bitvec_write_field(vector, writeIndex, fl, bits_to_handle);
               LOGPC(DCSN1, LOGL_NOTICE, "%u|", fl);
               remaining_bits_len -= bits_to_handle;
diff --git a/tests/rlcmac/RLCMACTest.cpp b/tests/rlcmac/RLCMACTest.cpp
index 66bc53c..0362f16 100644
--- a/tests/rlcmac/RLCMACTest.cpp
+++ b/tests/rlcmac/RLCMACTest.cpp
@@ -89,7 +89,7 @@ void testRlcMacDownlink()
 
 	std::string testData[] = {
 	"4e082500e3f1a81d080820800b2b2b2b2b2b2b2b2b2b2b", // Packet Downlink Assignment
-	"48282407a6a074227201000b2b2b2b2b2b2b2b2b2b2b2b", // Packet Uplink Assignment
+	"48282407a6a07422720100032b2b2b2b2b2b2b2b2b2b2b", // Packet Uplink Assignment
 	"47240c00400000000000000079eb2ac9402b2b2b2b2b2b", // Packet Uplink Ack Nack
 	"47283c367513ba333004242b2b2b2b2b2b2b2b2b2b2b2b"  // Packet Uplink Assignment
 	"4913e00850884013a8048b2b2b2b2b2b2b2b2b2b2b2b2b"
@@ -152,8 +152,8 @@ void testRlcMacUplink()
 	bitvec_unhex(resultVector, "2b2b2b2b2b2b2b2b2b2b2b2b2b2b2b2b2b2b2b2b2b2b2b");
 
 	std::string testData[] = {
-	"400e1e61d11f2b2b2b2b2b2b2b2b2b2b2b2b2b2b2b2b2b", // Packet Uplink Dummy Control Block
-	"400b8020000000000000002480e00b2b2b2b2b2b2b2b2b", // Packet Downlink Ack/Nack
+	"400e1e61d11d2b2b2b2b2b2b2b2b2b2b2b2b2b2b2b2b2b", // Packet Uplink Dummy Control Block
+	"400b8020000000000000002480e0032b2b2b2b2b2b2b2b", // Packet Downlink Ack/Nack
 	"4016713dc094270ca2ae57ef909006aa0fc0001f80222b"  // Packet Resource Request
 	"400a9020000000000000003010012a0800132b2b2b2b2b"
 	};
diff --git a/tests/rlcmac/RLCMACTest.ok b/tests/rlcmac/RLCMACTest.ok
index 99117ff..0b4e154 100644
--- a/tests/rlcmac/RLCMACTest.ok
+++ b/tests/rlcmac/RLCMACTest.ok
@@ -7,13 +7,13 @@ vector1 = 4e8250e3f1a81d882080b2b2b2b2b2b2b2b2b2b2b
 vector1 = 4e8250e3f1a81d882080b2b2b2b2b2b2b2b2b2b2b
 vector2 = 4e8250e3f1a81d882080b2b2b2b2b2b2b2b2b2b2b
 vector1 == vector2 : TRUE
-vector1 = 4828247a6a074227210b2b2b2b2b2b2b2b2b2b2b2b
+vector1 = 4828247a6a07422721032b2b2b2b2b2b2b2b2b2b2b
 =========Start DECODE===========
 +++++++++Finish DECODE++++++++++
 =========Start ENCODE=============
 +++++++++Finish ENCODE+++++++++++
-vector1 = 4828247a6a074227210b2b2b2b2b2b2b2b2b2b2b2b
-vector2 = 4828247a6a074227210b2b2b2b2b2b2b2b2b2b2b2b
+vector1 = 4828247a6a07422721032b2b2b2b2b2b2b2b2b2b2b
+vector2 = 4828247a6a07422721032b2b2b2b2b2b2b2b2b2b2b
 vector1 == vector2 : TRUE
 vector1 = 4724c040000000079eb2ac9402b2b2b2b2b2b
 =========Start DECODE===========
@@ -32,21 +32,21 @@ vector1 = 47283c367513ba33304242b2b2b2b2b2b2b2b2b2b2b2b
 vector2 = 47283c367513ba33304242b2b2b2b2b2b2b2b2b2b2b2b
 vector1 == vector2 : TRUE
  UPLINK 
-vector1 = 40e1e61d11f2b2b2b2b2b2b2b2b2b2b2b2b2b2b2b2b2b
+vector1 = 40e1e61d11d2b2b2b2b2b2b2b2b2b2b2b2b2b2b2b2b2b
 =========Start DECODE===========
 +++++++++Finish DECODE++++++++++
 =========Start ENCODE=============
 +++++++++Finish ENCODE+++++++++++
-vector1 = 40e1e61d11f2b2b2b2b2b2b2b2b2b2b2b2b2b2b2b2b2b
-vector2 = 40e1e61d11f2b2b2b2b2b2b2b2b2b2b2b2b2b2b2b2b2b
+vector1 = 40e1e61d11d2b2b2b2b2b2b2b2b2b2b2b2b2b2b2b2b2b
+vector2 = 40e1e61d11d2b2b2b2b2b2b2b2b2b2b2b2b2b2b2b2b2b
 vector1 == vector2 : TRUE
-vector1 = 40b802000000002480e0b2b2b2b2b2b2b2b2b
+vector1 = 40b802000000002480e032b2b2b2b2b2b2b2b
 =========Start DECODE===========
 +++++++++Finish DECODE++++++++++
 =========Start ENCODE=============
 +++++++++Finish ENCODE+++++++++++
-vector1 = 40b802000000002480e0b2b2b2b2b2b2b2b2b
-vector2 = 40b802000000002480e0b2b2b2b2b2b2b2b2b
+vector1 = 40b802000000002480e032b2b2b2b2b2b2b2b
+vector2 = 40b802000000002480e032b2b2b2b2b2b2b2b
 vector1 == vector2 : TRUE
 vector1 = 4016713dc09427ca2ae57ef90906aafc001f80222b
 =========Start DECODE===========
diff --git a/tests/tbf/TbfTest.err b/tests/tbf/TbfTest.err
index 7796659..de9b775 100644
--- a/tests/tbf/TbfTest.err
+++ b/tests/tbf/TbfTest.err
@@ -3430,7 +3430,7 @@ TBF(TFI=0 TLLI=0xffeeddcc DIR=DL STATE=FLOW EGPRS)  start Packet Downlink Assign
 TBF(TFI=0 TLLI=0xffeeddcc DIR=DL STATE=FLOW EGPRS): Scheduling polling at FN 13 TS 4
 TBF(TFI=0 TLLI=0xffeeddcc DIR=DL STATE=FLOW EGPRS) Scheduled DL Assignment polling on FN=13, TS=4
 Scheduling control message at RTS for TBF(TFI=0 TLLI=0xffeeddcc DIR=DL STATE=FLOW EGPRS) (TRX=0, TS=4)
-Sending data request: trx=0 ts=4 sapi=5 arfcn=0 fn=0 block=0 data=4f 08 20 00 44 02 00 02 08 04 00 c0 0b 2b 2b 2b 2b 2b 2b 2b 2b 2b 2b 
+Sending data request: trx=0 ts=4 sapi=5 arfcn=0 fn=0 block=0 data=4f 08 20 00 44 02 00 02 08 04 00 c0 03 2b 2b 2b 2b 2b 2b 2b 2b 2b 2b 
 Scheduling data message at RTS for DL TFI=0 (TRX=0, TS=4) prio=3
 TBF(TFI=0 TLLI=0xffeeddcc DIR=DL STATE=FLOW EGPRS) downlink (V(A)==0 .. V(S)==0)
 - Sending new block at BSN 0, CS=MCS-1
@@ -3738,7 +3738,7 @@ TBF(TFI=0 TLLI=0xffeeddcc DIR=DL STATE=FLOW EGPRS)  start Packet Downlink Assign
 TBF(TFI=0 TLLI=0xffeeddcc DIR=DL STATE=FLOW EGPRS): Scheduling polling at FN 13 TS 4
 TBF(TFI=0 TLLI=0xffeeddcc DIR=DL STATE=FLOW EGPRS) Scheduled DL Assignment polling on FN=13, TS=4
 Scheduling control message at RTS for TBF(TFI=0 TLLI=0xffeeddcc DIR=DL STATE=FLOW EGPRS) (TRX=0, TS=4)
-Sending data request: trx=0 ts=4 sapi=5 arfcn=0 fn=0 block=0 data=4f 08 20 00 44 02 00 02 08 04 00 c0 0b 2b 2b 2b 2b 2b 2b 2b 2b 2b 2b 
+Sending data request: trx=0 ts=4 sapi=5 arfcn=0 fn=0 block=0 data=4f 08 20 00 44 02 00 02 08 04 00 c0 03 2b 2b 2b 2b 2b 2b 2b 2b 2b 2b 
 Scheduling data message at RTS for DL TFI=0 (TRX=0, TS=4) prio=3
 TBF(TFI=0 TLLI=0xffeeddcc DIR=DL STATE=FLOW EGPRS) downlink (V(A)==0 .. V(S)==0)
 - Sending new block at BSN 0, CS=MCS-2
@@ -3996,7 +3996,7 @@ TBF(TFI=0 TLLI=0xffeeddcc DIR=DL STATE=FLOW EGPRS)  start Packet Downlink Assign
 TBF(TFI=0 TLLI=0xffeeddcc DIR=DL STATE=FLOW EGPRS): Scheduling polling at FN 13 TS 4
 TBF(TFI=0 TLLI=0xffeeddcc DIR=DL STATE=FLOW EGPRS) Scheduled DL Assignment polling on FN=13, TS=4
 Scheduling control message at RTS for TBF(TFI=0 TLLI=0xffeeddcc DIR=DL STATE=FLOW EGPRS) (TRX=0, TS=4)
-Sending data request: trx=0 ts=4 sapi=5 arfcn=0 fn=0 block=0 data=4f 08 20 00 44 02 00 02 08 04 00 c0 0b 2b 2b 2b 2b 2b 2b 2b 2b 2b 2b 
+Sending data request: trx=0 ts=4 sapi=5 arfcn=0 fn=0 block=0 data=4f 08 20 00 44 02 00 02 08 04 00 c0 03 2b 2b 2b 2b 2b 2b 2b 2b 2b 2b 
 Scheduling data message at RTS for DL TFI=0 (TRX=0, TS=4) prio=3
 TBF(TFI=0 TLLI=0xffeeddcc DIR=DL STATE=FLOW EGPRS) downlink (V(A)==0 .. V(S)==0)
 - Sending new block at BSN 0, CS=MCS-3
@@ -4217,7 +4217,7 @@ TBF(TFI=0 TLLI=0xffeeddcc DIR=DL STATE=FLOW EGPRS)  start Packet Downlink Assign
 TBF(TFI=0 TLLI=0xffeeddcc DIR=DL STATE=FLOW EGPRS): Scheduling polling at FN 13 TS 4
 TBF(TFI=0 TLLI=0xffeeddcc DIR=DL STATE=FLOW EGPRS) Scheduled DL Assignment polling on FN=13, TS=4
 Scheduling control message at RTS for TBF(TFI=0 TLLI=0xffeeddcc DIR=DL STATE=FLOW EGPRS) (TRX=0, TS=4)
-Sending data request: trx=0 ts=4 sapi=5 arfcn=0 fn=0 block=0 data=4f 08 20 00 44 02 00 02 08 04 00 c0 0b 2b 2b 2b 2b 2b 2b 2b 2b 2b 2b 
+Sending data request: trx=0 ts=4 sapi=5 arfcn=0 fn=0 block=0 data=4f 08 20 00 44 02 00 02 08 04 00 c0 03 2b 2b 2b 2b 2b 2b 2b 2b 2b 2b 
 Scheduling data message at RTS for DL TFI=0 (TRX=0, TS=4) prio=3
 TBF(TFI=0 TLLI=0xffeeddcc DIR=DL STATE=FLOW EGPRS) downlink (V(A)==0 .. V(S)==0)
 - Sending new block at BSN 0, CS=MCS-4
@@ -4405,7 +4405,7 @@ TBF(TFI=0 TLLI=0xffeeddcc DIR=DL STATE=FLOW EGPRS)  start Packet Downlink Assign
 TBF(TFI=0 TLLI=0xffeeddcc DIR=DL STATE=FLOW EGPRS): Scheduling polling at FN 13 TS 4
 TBF(TFI=0 TLLI=0xffeeddcc DIR=DL STATE=FLOW EGPRS) Scheduled DL Assignment polling on FN=13, TS=4
 Scheduling control message at RTS for TBF(TFI=0 TLLI=0xffeeddcc DIR=DL STATE=FLOW EGPRS) (TRX=0, TS=4)
-Sending data request: trx=0 ts=4 sapi=5 arfcn=0 fn=0 block=0 data=4f 08 20 00 44 02 00 02 08 04 00 c0 0b 2b 2b 2b 2b 2b 2b 2b 2b 2b 2b 
+Sending data request: trx=0 ts=4 sapi=5 arfcn=0 fn=0 block=0 data=4f 08 20 00 44 02 00 02 08 04 00 c0 03 2b 2b 2b 2b 2b 2b 2b 2b 2b 2b 
 Scheduling data message at RTS for DL TFI=0 (TRX=0, TS=4) prio=3
 TBF(TFI=0 TLLI=0xffeeddcc DIR=DL STATE=FLOW EGPRS) downlink (V(A)==0 .. V(S)==0)
 - Sending new block at BSN 0, CS=MCS-5
@@ -4573,7 +4573,7 @@ TBF(TFI=0 TLLI=0xffeeddcc DIR=DL STATE=FLOW EGPRS)  start Packet Downlink Assign
 TBF(TFI=0 TLLI=0xffeeddcc DIR=DL STATE=FLOW EGPRS): Scheduling polling at FN 13 TS 4
 TBF(TFI=0 TLLI=0xffeeddcc DIR=DL STATE=FLOW EGPRS) Scheduled DL Assignment polling on FN=13, TS=4
 Scheduling control message at RTS for TBF(TFI=0 TLLI=0xffeeddcc DIR=DL STATE=FLOW EGPRS) (TRX=0, TS=4)
-Sending data request: trx=0 ts=4 sapi=5 arfcn=0 fn=0 block=0 data=4f 08 20 00 44 02 00 02 08 04 00 c0 0b 2b 2b 2b 2b 2b 2b 2b 2b 2b 2b 
+Sending data request: trx=0 ts=4 sapi=5 arfcn=0 fn=0 block=0 data=4f 08 20 00 44 02 00 02 08 04 00 c0 03 2b 2b 2b 2b 2b 2b 2b 2b 2b 2b 
 Scheduling data message at RTS for DL TFI=0 (TRX=0, TS=4) prio=3
 TBF(TFI=0 TLLI=0xffeeddcc DIR=DL STATE=FLOW EGPRS) downlink (V(A)==0 .. V(S)==0)
 - Sending new block at BSN 0, CS=MCS-6
@@ -4724,7 +4724,7 @@ TBF(TFI=0 TLLI=0xffeeddcc DIR=DL STATE=FLOW EGPRS)  start Packet Downlink Assign
 TBF(TFI=0 TLLI=0xffeeddcc DIR=DL STATE=FLOW EGPRS): Scheduling polling at FN 13 TS 4
 TBF(TFI=0 TLLI=0xffeeddcc DIR=DL STATE=FLOW EGPRS) Scheduled DL Assignment polling on FN=13, TS=4
 Scheduling control message at RTS for TBF(TFI=0 TLLI=0xffeeddcc DIR=DL STATE=FLOW EGPRS) (TRX=0, TS=4)
-Sending data request: trx=0 ts=4 sapi=5 arfcn=0 fn=0 block=0 data=4f 08 20 00 44 02 00 02 08 04 00 c0 0b 2b 2b 2b 2b 2b 2b 2b 2b 2b 2b 
+Sending data request: trx=0 ts=4 sapi=5 arfcn=0 fn=0 block=0 data=4f 08 20 00 44 02 00 02 08 04 00 c0 03 2b 2b 2b 2b 2b 2b 2b 2b 2b 2b 
 Scheduling data message at RTS for DL TFI=0 (TRX=0, TS=4) prio=3
 TBF(TFI=0 TLLI=0xffeeddcc DIR=DL STATE=FLOW EGPRS) downlink (V(A)==0 .. V(S)==0)
 - Sending new block at BSN 0, CS=MCS-7
@@ -4872,7 +4872,7 @@ TBF(TFI=0 TLLI=0xffeeddcc DIR=DL STATE=FLOW EGPRS)  start Packet Downlink Assign
 TBF(TFI=0 TLLI=0xffeeddcc DIR=DL STATE=FLOW EGPRS): Scheduling polling at FN 13 TS 4
 TBF(TFI=0 TLLI=0xffeeddcc DIR=DL STATE=FLOW EGPRS) Scheduled DL Assignment polling on FN=13, TS=4
 Scheduling control message at RTS for TBF(TFI=0 TLLI=0xffeeddcc DIR=DL STATE=FLOW EGPRS) (TRX=0, TS=4)
-Sending data request: trx=0 ts=4 sapi=5 arfcn=0 fn=0 block=0 data=4f 08 20 00 44 02 00 02 08 04 00 c0 0b 2b 2b 2b 2b 2b 2b 2b 2b 2b 2b 
+Sending data request: trx=0 ts=4 sapi=5 arfcn=0 fn=0 block=0 data=4f 08 20 00 44 02 00 02 08 04 00 c0 03 2b 2b 2b 2b 2b 2b 2b 2b 2b 2b 
 Scheduling data message at RTS for DL TFI=0 (TRX=0, TS=4) prio=3
 TBF(TFI=0 TLLI=0xffeeddcc DIR=DL STATE=FLOW EGPRS) downlink (V(A)==0 .. V(S)==0)
 - Sending new block at BSN 0, CS=MCS-8
@@ -5008,7 +5008,7 @@ TBF(TFI=0 TLLI=0xffeeddcc DIR=DL STATE=FLOW EGPRS)  start Packet Downlink Assign
 TBF(TFI=0 TLLI=0xffeeddcc DIR=DL STATE=FLOW EGPRS): Scheduling polling at FN 13 TS 4
 TBF(TFI=0 TLLI=0xffeeddcc DIR=DL STATE=FLOW EGPRS) Scheduled DL Assignment polling on FN=13, TS=4
 Scheduling control message at RTS for TBF(TFI=0 TLLI=0xffeeddcc DIR=DL STATE=FLOW EGPRS) (TRX=0, TS=4)
-Sending data request: trx=0 ts=4 sapi=5 arfcn=0 fn=0 block=0 data=4f 08 20 00 44 02 00 02 08 04 00 c0 0b 2b 2b 2b 2b 2b 2b 2b 2b 2b 2b 
+Sending data request: trx=0 ts=4 sapi=5 arfcn=0 fn=0 block=0 data=4f 08 20 00 44 02 00 02 08 04 00 c0 03 2b 2b 2b 2b 2b 2b 2b 2b 2b 2b 
 Scheduling data message at RTS for DL TFI=0 (TRX=0, TS=4) prio=3
 TBF(TFI=0 TLLI=0xffeeddcc DIR=DL STATE=FLOW EGPRS) downlink (V(A)==0 .. V(S)==0)
 - Sending new block at BSN 0, CS=MCS-9
