diff --git a/library/network/protocol/http/src/http_header.e b/library/network/protocol/http/src/http_header.e
index e3a8956a..001067a9 100644
--- a/library/network/protocol/http/src/http_header.e
+++ b/library/network/protocol/http/src/http_header.e
@@ -22,7 +22,7 @@ class
 	HTTP_HEADER
 
 inherit
-	ANY
+	ITERABLE [READABLE_STRING_8]
 
 create
 	make,
@@ -149,6 +149,14 @@ feature -- Access
 			Result := res
 		end
 
+feature -- Access
+
+	new_cursor: INDEXABLE_ITERATION_CURSOR [READABLE_STRING_8]
+			-- Fresh cursor associated with current structure
+		do
+			Result := headers.new_cursor
+		end
+
 feature -- Header: filling
 
 	append_array (a_headers: ARRAY [TUPLE [key: READABLE_STRING_8; value: READABLE_STRING_8]])
diff --git a/library/server/wsf/src/response/wsf_trace_response.e b/library/server/wsf/src/response/wsf_trace_response.e
index 4b287d08..3b559e7a 100644
--- a/library/server/wsf/src/response/wsf_trace_response.e
+++ b/library/server/wsf/src/response/wsf_trace_response.e
@@ -47,16 +47,15 @@ feature {WSF_RESPONSE} -- Output
 				s.append (l_header.to_string_8)
 				s.append_character ('%N')
 			else
-				s := ""
+				create s.make_empty
 			end
 			if req.is_chunked_input then
 				h.put_transfer_encoding_chunked
 				res.put_header_text (h.string)
 				res.put_chunk (s, Void)
 				if attached req.input as l_input then
-
 					from
-						n := 1_024
+						n := 8_192
 					until
 						n = 0
 					loop
diff --git a/library/server/wsf/src/wsf_response.e b/library/server/wsf/src/wsf_response.e
index 3921c4ab..edd69fed 100644
--- a/library/server/wsf/src/wsf_response.e
+++ b/library/server/wsf/src/wsf_response.e
@@ -183,7 +183,7 @@ feature {NONE} -- Implementation
 			transfered_content_length := transfered_content_length + n.to_natural_64
 		end
 
-feature -- Output operation
+feature -- Body
 
 	put_character (c: CHARACTER_8)
 			-- Send the character `c'
@@ -212,20 +212,23 @@ feature -- Output operation
 			increment_transfered_content_length (a_end_index - a_begin_index + 1)
 		end
 
-	put_chunk (s: READABLE_STRING_8; a_extension: detachable READABLE_STRING_8)
-			-- Write chunk non empty `s'
-			-- Note: that you should have header
-			-- "Transfer-Encoding: chunked"
+feature -- Chunk body
+
+	put_chunk (a_content: READABLE_STRING_8; a_ext: detachable READABLE_STRING_8)
+			-- Write chunk non empty `a_content'
+			-- with optional extension `a_ext': chunk-extension= *( ";" chunk-ext-name [ "=" chunk-ext-val ] )
+			-- Note: that you should have header "Transfer-Encoding: chunked"
 		require
-			s_not_empty: s /= Void and then not s.is_empty
+			a_content_not_empty: a_content /= Void and then not a_content.is_empty
 			message_writable: message_writable
-			valid_chunk_extension: a_extension /= Void implies not a_extension.has ('%N') and not not a_extension.has ('%R')
+			valid_chunk_extension: (a_ext /= Void and then not a_ext.is_empty) implies
+						( a_ext.starts_with (";") and not a_ext.has ('%N') and not not a_ext.has ('%R') )
 		local
 			l_chunk_size_line: STRING_8
 			i: INTEGER
 		do
 				--| Remove all left '0'
-			l_chunk_size_line := s.count.to_hex_string
+			l_chunk_size_line := a_content.count.to_hex_string
 			from
 				i := 1
 			until
@@ -237,42 +240,52 @@ feature -- Output operation
 				l_chunk_size_line := l_chunk_size_line.substring (i, l_chunk_size_line.count)
 			end
 
-			if a_extension /= Void then
-				l_chunk_size_line.append_character (';')
-				l_chunk_size_line.append (a_extension)
+			if a_ext /= Void then
+				l_chunk_size_line.append (a_ext)
 			end
 			l_chunk_size_line.append ({HTTP_CONSTANTS}.crlf)
 
 
 			wgi_response.put_string (l_chunk_size_line)
-			put_string (s)
+			put_string (a_content)
 			wgi_response.put_string ({HTTP_CONSTANTS}.crlf)
 			flush
 		ensure
-			transfered_content_length =  old transfered_content_length + s.count.to_natural_64
+			transfered_content_length =  old transfered_content_length + a_content.count.to_natural_64
+		end
+
+	put_custom_chunk_end (a_ext: detachable READABLE_STRING_8; a_trailer: detachable READABLE_STRING_8)
+			-- Put end of chunked content,
+			-- with optional extension `a_ext': chunk-extension= *( ";" chunk-ext-name [ "=" chunk-ext-val ] )
+			-- and with optional trailer `a_trailer' : trailer= *(entity-header CRLF)
+		local
+			l_chunk_size_line: STRING_8
+		do
+			-- Chunk end
+			create l_chunk_size_line.make (1)
+			l_chunk_size_line.append_integer (0)
+
+			if a_ext /= Void then
+				l_chunk_size_line.append (a_ext)
+			end
+			l_chunk_size_line.append ({HTTP_CONSTANTS}.crlf)
+			wgi_response.put_string (l_chunk_size_line)
+
+			-- Optional trailer
+			if a_trailer /= Void and then not a_trailer.is_empty then
+				wgi_response.put_string (a_trailer)
+			end
+
+			-- Final CRLF
+			wgi_response.put_string ({HTTP_CONSTANTS}.crlf)
+			flush
 		end
 
 	put_chunk_end
 			-- Put end of chunked content
 			-- without any optional trailer.
 		do
-			wgi_response.put_string ("0")
-			wgi_response.put_string ({HTTP_CONSTANTS}.crlf)
-			-- No trailer
-			wgi_response.put_string ({HTTP_CONSTANTS}.crlf)
-			flush
-		end
-
-	put_chunk_end_with_trailer (a_trailer: detachable READABLE_STRING_8)
-			-- Put end of chunked content
-			-- with optional trailer: *(entity-header CRLF)
-		require
-			a_trailer_well_formatted: (a_trailer /= Void and then not a_trailer.is_empty) implies a_trailer.ends_with ({HTTP_CONSTANTS}.crlf)
-		do
-			if a_trailer /= Void and then not a_trailer.is_empty then
-				wgi_response.put_string (a_trailer)
-			end
-			wgi_response.put_string ({HTTP_CONSTANTS}.crlf)
+			put_custom_chunk_end (Void, Void)
 		end
 
 	flush