diff --git a/README b/README
index 34a6633..cf83c56 100644
--- a/README
+++ b/README
@@ -83,6 +83,7 @@ Supported MPEG descriptors
  * Descriptor 0x1d: IOD_descriptor
  * Descriptor 0x1e: SL_descriptor
  * Descriptor 0x1f: FMC_descriptor
+ * Descriptor 0x20: External ES_ID descriptor
 
 
 Supported DVB descriptors
diff --git a/TODO b/TODO
index 1b60c88..9dc49d3 100644
--- a/TODO
+++ b/TODO
@@ -2,7 +2,6 @@ TODO items for biTStream. The items are not ordered by importance
 so if you like something just do it and send a patch.
 
 - Add support (parser, generator, example) for these MPEG descriptors:
-  - Descriptor 0x20 external_ES_ID_descriptor
   - Descriptor 0x21 MuxCode_descriptor
   - Descriptor 0x22 FmxBufferSize_descriptor
   - Descriptor 0x23 multiplexbuffer_descriptor
diff --git a/examples/dvb_gen_si.c b/examples/dvb_gen_si.c
index a32505c..a3d79cb 100644
--- a/examples/dvb_gen_si.c
+++ b/examples/dvb_gen_si.c
@@ -275,6 +275,13 @@ static void build_desc1f(uint8_t *desc) {
     desc_set_length(desc, entry_n - desc - DESC1F_HEADER_SIZE);
 }
 
+/* MPEG Descriptor 0x20: External ES_ID descriptor */
+static void build_desc20(uint8_t *desc) {
+    desc20_init(desc);
+    desc20_set_external_es_id(desc, 0x1234);
+}
+
+
 /* =========================================================================
  * DVB defined descriptors
  * ========================================================================= */
@@ -1639,6 +1646,9 @@ static void generate_pmt(void) {
             desc = descs_get_desc(desc_loop, desc_counter++);
             build_desc1f(desc);
 
+            desc = descs_get_desc(desc_loop, desc_counter++);
+            build_desc20(desc);
+
             // Finish descriptor generation
             desc = descs_get_desc(desc_loop, desc_counter); // Get next descriptor pos
             descs_set_length(desc_loop, desc - desc_loop - DESCS_HEADER_SIZE);
diff --git a/mpeg/psi/desc_20.h b/mpeg/psi/desc_20.h
new file mode 100644
index 0000000..a07b4fd
--- /dev/null
+++ b/mpeg/psi/desc_20.h
@@ -0,0 +1,78 @@
+/*****************************************************************************
+ * desc_20.h: ISO/IEC 13818-1 Descriptor 0x20 (External ES_ID descriptor)
+ *****************************************************************************
+ * Copyright (C) 2011 Unix Solutions Ltd.
+ *
+ * Authors: Georgi Chorbadzhiyski <georgi@unixsol.org>
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining
+ * a copy of this software and associated documentation files (the
+ * "Software"), to deal in the Software without restriction, including
+ * without limitation the rights to use, copy, modify, merge, publish,
+ * distribute, sublicense, and/or sell copies of the Software, and to
+ * permit persons to whom the Software is furnished to do so, subject
+ * to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be
+ * included in all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
+ * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
+ * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.
+ * IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY
+ * CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT,
+ * TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE
+ * SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
+ *****************************************************************************/
+
+/*
+ * Normative references:
+ *  - ISO/IEC 13818-1:2007(E) (MPEG-2 Systems)
+ */
+
+#ifndef __BITSTREAM_MPEG_DESC_20_H__
+#define __BITSTREAM_MPEG_DESC_20_H__
+
+#include <bitstream/common.h>
+#include <bitstream/mpeg/psi/descriptors.h>
+#include <bitstream/mpeg/psi/desc_1e.h>
+
+#ifdef __cplusplus
+extern "C"
+{
+#endif
+
+/*****************************************************************************
+ * Descriptor 0x20 (External ES_ID descriptor)
+ *****************************************************************************/
+#define DESC20_HEADER_SIZE      (DESC_HEADER_SIZE + 2)
+
+static inline void desc20_init(uint8_t *p_desc)
+{
+    desc_set_tag(p_desc, 0x20);
+    desc_set_length(p_desc, DESC20_HEADER_SIZE - DESC_HEADER_SIZE);
+}
+
+#define desc20_validate           desc1e_validate
+#define desc20_get_external_es_id desc1e_get_es_id
+#define desc20_set_external_es_id desc1e_set_es_id
+
+static inline void desc20_print(const uint8_t *p_desc, f_print pf_print,
+                                void *opaque, print_type_t i_print_type)
+{
+    switch (i_print_type) {
+    case PRINT_XML:
+        pf_print(opaque, "<EXTERNAL_ES_ID_DESC external_es_id=\"0x%04x\"/>",
+                 desc20_get_external_es_id(p_desc));
+        break;
+    default:
+        pf_print(opaque,"    - desc 20 external_es_id external_es_id=0x%04x",
+                 desc20_get_external_es_id(p_desc));
+    }
+}
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif
diff --git a/mpeg/psi/descs_list.h b/mpeg/psi/descs_list.h
index 826ccc4..a5083c2 100644
--- a/mpeg/psi/descs_list.h
+++ b/mpeg/psi/descs_list.h
@@ -56,5 +56,6 @@
 #include <bitstream/mpeg/psi/desc_1d.h>
 #include <bitstream/mpeg/psi/desc_1e.h>
 #include <bitstream/mpeg/psi/desc_1f.h>
+#include <bitstream/mpeg/psi/desc_20.h>
 
 #endif
diff --git a/mpeg/psi/descs_print.h b/mpeg/psi/descs_print.h
index a2a3f1f..581dd80 100644
--- a/mpeg/psi/descs_print.h
+++ b/mpeg/psi/descs_print.h
@@ -122,6 +122,7 @@ static inline void descl_print(uint8_t *p_descl, uint16_t i_length,
         CASE_DESC(1d)
         CASE_DESC(1e)
         CASE_DESC(1f)
+        CASE_DESC(20)
         CASE_DESC_ICONV(40)
         CASE_DESC(41)
         CASE_DESC(43)