diff --git a/CHANGELOG.md b/CHANGELOG.md
index ed2f4064..6b0066d3 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -1,3 +1,9 @@
+1.0.0-b28
+
+* Split out and rename test stream classes
+
+--------------------------------------------------------------------------------
+
 1.0.0-b27
 
 * Tidy up tests and docs
diff --git a/extras/beast/test/string_stream.hpp b/extras/beast/test/string_istream.hpp
similarity index 86%
rename from extras/beast/test/string_stream.hpp
rename to extras/beast/test/string_istream.hpp
index ba4439f7..2ff07448 100644
--- a/extras/beast/test/string_stream.hpp
+++ b/extras/beast/test/string_istream.hpp
@@ -5,12 +5,13 @@
 // file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
 //
 
-#ifndef BEAST_TEST_STRING_STREAM_HPP
-#define BEAST_TEST_STRING_STREAM_HPP
+#ifndef BEAST_TEST_STRING_ISTREAM_HPP
+#define BEAST_TEST_STRING_ISTREAM_HPP
 
 #include <beast/core/async_completion.hpp>
 #include <beast/core/bind_handler.hpp>
 #include <beast/core/error.hpp>
+#include <beast/core/prepare_buffer.hpp>
 #include <boost/asio/buffer.hpp>
 #include <boost/asio/io_service.hpp>
 #include <string>
@@ -24,16 +25,21 @@ namespace test {
     discarded, and when data is read it comes from a string provided
     at construction.
 */
-class string_stream
+class string_istream
 {
     std::string s_;
+    boost::asio::const_buffer cb_;
     boost::asio::io_service& ios_;
+    std::size_t read_max_;
 
 public:
-    string_stream(boost::asio::io_service& ios,
-            std::string s)
+    string_istream(boost::asio::io_service& ios,
+            std::string s, std::size_t read_max =
+                (std::numeric_limits<std::size_t>::max)())
         : s_(std::move(s))
+        , cb_(boost::asio::buffer(s_))
         , ios_(ios)
+        , read_max_(read_max)
     {
     }
 
@@ -60,9 +66,9 @@ public:
         error_code& ec)
     {
         auto const n = boost::asio::buffer_copy(
-            buffers, boost::asio::buffer(s_));
+            buffers, prepare_buffer(read_max_, cb_));
         if(n > 0)
-            s_.erase(0, n);
+            cb_ = cb_ + n;
         else
             ec = boost::asio::error::eof;
         return n;
diff --git a/extras/beast/test/string_ostream.hpp b/extras/beast/test/string_ostream.hpp
new file mode 100644
index 00000000..63a6f110
--- /dev/null
+++ b/extras/beast/test/string_ostream.hpp
@@ -0,0 +1,118 @@
+//
+// Copyright (c) 2013-2017 Vinnie Falco (vinnie dot falco at gmail dot com)
+//
+// Distributed under the Boost Software License, Version 1.0. (See accompanying
+// file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
+//
+
+#ifndef BEAST_TEST_STRING_OSTREAM_HPP
+#define BEAST_TEST_STRING_OSTREAM_HPP
+
+#include <beast/core/async_completion.hpp>
+#include <beast/core/bind_handler.hpp>
+#include <beast/core/error.hpp>
+#include <boost/asio/buffer.hpp>
+#include <boost/asio/io_service.hpp>
+#include <string>
+
+namespace beast {
+namespace test {
+
+class string_ostream
+{
+    boost::asio::io_service& ios_;
+
+public:
+    std::string str;
+
+    explicit
+    string_ostream(boost::asio::io_service& ios)
+        : ios_(ios)
+    {
+    }
+
+    boost::asio::io_service&
+    get_io_service()
+    {
+        return ios_;
+    }
+
+    template<class MutableBufferSequence>
+    std::size_t
+    read_some(MutableBufferSequence const& buffers)
+    {
+        error_code ec;
+        auto const n = read_some(buffers, ec);
+        if(ec)
+            throw system_error{ec};
+        return n;
+    }
+
+    template<class MutableBufferSequence>
+    std::size_t
+    read_some(MutableBufferSequence const& buffers,
+        error_code& ec)
+    {
+        return 0;
+    }
+
+    template<class MutableBufferSequence, class ReadHandler>
+    typename async_completion<ReadHandler,
+        void(error_code, std::size_t)>::result_type
+    async_read_some(MutableBufferSequence const& buffers,
+        ReadHandler&& handler)
+    {
+        async_completion<ReadHandler,
+            void(error_code, std::size_t)> completion{handler};
+        ios_.post(bind_handler(completion.handler,
+            error_code{}, 0));
+        return completion.result.get();
+    }
+
+    template<class ConstBufferSequence>
+    std::size_t
+    write_some(ConstBufferSequence const& buffers)
+    {
+        error_code ec;
+        auto const n = write_some(buffers, ec);
+        if(ec)
+            throw system_error{ec};
+        return n;
+    }
+
+    template<class ConstBufferSequence>
+    std::size_t
+    write_some(
+        ConstBufferSequence const& buffers, error_code&)
+    {
+        auto const n = buffer_size(buffers);
+        using boost::asio::buffer_size;
+        using boost::asio::buffer_cast;
+        str.reserve(str.size() + n);
+        for(auto const& buffer : buffers)
+            str.append(buffer_cast<char const*>(buffer),
+                buffer_size(buffer));
+        return n;
+    }
+
+    template<class ConstBufferSequence, class WriteHandler>
+    typename async_completion<
+        WriteHandler, void(error_code)>::result_type
+    async_write_some(ConstBufferSequence const& buffers,
+        WriteHandler&& handler)
+    {
+        error_code ec;
+        auto const bytes_transferred = write_some(buffers, ec);
+        async_completion<
+            WriteHandler, void(error_code, std::size_t)
+                > completion(handler);
+        get_io_service().post(
+            bind_handler(completion.handler, ec, bytes_transferred));
+        return completion.result.get();
+    }
+};
+
+} // test
+} // beast
+
+#endif
diff --git a/test/core/dynabuf_readstream.cpp b/test/core/dynabuf_readstream.cpp
index a334b207..1293e523 100644
--- a/test/core/dynabuf_readstream.cpp
+++ b/test/core/dynabuf_readstream.cpp
@@ -10,7 +10,7 @@
 
 #include <beast/core/streambuf.hpp>
 #include <beast/test/fail_stream.hpp>
-#include <beast/test/string_stream.hpp>
+#include <beast/test/string_istream.hpp>
 #include <beast/test/yield_to.hpp>
 #include <beast/unit_test/suite.hpp>
 #include <boost/asio.hpp>
@@ -54,7 +54,7 @@ public:
         for(n = 0; n < limit; ++n)
         {
             test::fail_stream<
-                test::string_stream> fs(n, ios_, ", world!");
+                test::string_istream> fs(n, ios_, ", world!");
             dynabuf_readstream<
                 decltype(fs)&, streambuf> srs(fs);
             srs.buffer().commit(buffer_copy(
@@ -72,7 +72,7 @@ public:
         for(n = 0; n < limit; ++n)
         {
             test::fail_stream<
-                test::string_stream> fs(n, ios_, ", world!");
+                test::string_istream> fs(n, ios_, ", world!");
             dynabuf_readstream<
                 decltype(fs)&, streambuf> srs(fs);
             srs.capacity(3);
@@ -91,7 +91,7 @@ public:
         for(n = 0; n < limit; ++n)
         {
             test::fail_stream<
-                test::string_stream> fs(n, ios_, ", world!");
+                test::string_istream> fs(n, ios_, ", world!");
             dynabuf_readstream<
                 decltype(fs)&, streambuf> srs(fs);
             srs.buffer().commit(buffer_copy(
@@ -110,7 +110,7 @@ public:
         for(n = 0; n < limit; ++n)
         {
             test::fail_stream<
-                test::string_stream> fs(n, ios_, ", world!");
+                test::string_istream> fs(n, ios_, ", world!");
             dynabuf_readstream<
                 decltype(fs)&, streambuf> srs(fs);
             srs.capacity(3);
diff --git a/test/http/parser_v1.cpp b/test/http/parser_v1.cpp
index 27012214..e9df99f3 100644
--- a/test/http/parser_v1.cpp
+++ b/test/http/parser_v1.cpp
@@ -13,7 +13,7 @@
 #include <beast/http/header_parser_v1.hpp>
 #include <beast/http/parse.hpp>
 #include <beast/http/string_body.hpp>
-#include <beast/test/string_stream.hpp>
+#include <beast/test/string_istream.hpp>
 #include <beast/test/yield_to.hpp>
 #include <beast/unit_test/suite.hpp>
 
@@ -55,7 +55,7 @@ public:
 
     void testWithBody()
     {
-        test::string_stream ss{ios_,
+        test::string_istream ss{ios_,
             "GET / HTTP/1.1\r\n"
             "User-Agent: test\r\n"
             "Content-Length: 1\r\n"
diff --git a/test/http/read.cpp b/test/http/read.cpp
index 356610d1..bd4cde26 100644
--- a/test/http/read.cpp
+++ b/test/http/read.cpp
@@ -13,7 +13,7 @@
 #include <beast/http/fields.hpp>
 #include <beast/http/streambuf_body.hpp>
 #include <beast/test/fail_stream.hpp>
-#include <beast/test/string_stream.hpp>
+#include <beast/test/string_istream.hpp>
 #include <beast/test/yield_to.hpp>
 #include <beast/unit_test/suite.hpp>
 #include <boost/asio/spawn.hpp>
@@ -95,7 +95,7 @@ public:
                 sb.prepare(len), buffer(s, len)));
             test::fail_counter fc(n);
             test::fail_stream<
-                test::string_stream> fs{fc, ios_, ""};
+                test::string_istream> fs{fc, ios_, ""};
             fail_parser<isRequest> p(fc);
             error_code ec;
             parse(fs, sb, p, ec);
@@ -110,7 +110,7 @@ public:
             sb.commit(buffer_copy(
                 sb.prepare(pre), buffer(s, pre)));
             test::fail_counter fc(n);
-            test::fail_stream<test::string_stream> fs{
+            test::fail_stream<test::string_istream> fs{
                 fc, ios_, std::string{s + pre, len - pre}};
             fail_parser<isRequest> p(fc);
             error_code ec;
@@ -126,7 +126,7 @@ public:
                 sb.prepare(len), buffer(s, len)));
             test::fail_counter fc(n);
             test::fail_stream<
-                test::string_stream> fs{fc, ios_, ""};
+                test::string_istream> fs{fc, ios_, ""};
             fail_parser<isRequest> p(fc);
             error_code ec;
             async_parse(fs, sb, p, do_yield[ec]);
@@ -141,7 +141,7 @@ public:
             sb.commit(buffer_copy(
                 sb.prepare(pre), buffer(s, pre)));
             test::fail_counter fc(n);
-            test::fail_stream<test::string_stream> fs{
+            test::fail_stream<test::string_istream> fs{
                 fc, ios_, std::string{s + pre, len - pre}};
             fail_parser<isRequest> p(fc);
             error_code ec;
@@ -156,7 +156,7 @@ public:
             sb.commit(buffer_copy(
                 sb.prepare(len), buffer(s, len)));
             test::fail_counter fc{n};
-            test::string_stream ss{ios_, s};
+            test::string_istream ss{ios_, s};
             parser_v1<isRequest, fail_body, fields> p{fc};
             error_code ec;
             parse(ss, sb, p, ec);
@@ -171,7 +171,7 @@ public:
         try
         {
             streambuf sb;
-            test::string_stream ss(ios_, "GET / X");
+            test::string_istream ss(ios_, "GET / X");
             parser_v1<true, streambuf_body, fields> p;
             parse(ss, sb, p);
             fail();
@@ -251,7 +251,7 @@ public:
 
         for(n = 0; n < limit; ++n)
         {
-            test::fail_stream<test::string_stream> fs{n, ios_,
+            test::fail_stream<test::string_istream> fs{n, ios_,
                 "GET / HTTP/1.1\r\n"
                 "Host: localhost\r\n"
                 "User-Agent: test\r\n"
@@ -273,7 +273,7 @@ public:
 
         for(n = 0; n < limit; ++n)
         {
-            test::fail_stream<test::string_stream> fs(n, ios_,
+            test::fail_stream<test::string_istream> fs(n, ios_,
                 "GET / HTTP/1.1\r\n"
                 "Host: localhost\r\n"
                 "User-Agent: test\r\n"
@@ -297,7 +297,7 @@ public:
 
         for(n = 0; n < limit; ++n)
         {
-            test::fail_stream<test::string_stream> fs(n, ios_,
+            test::fail_stream<test::string_istream> fs(n, ios_,
                 "GET / HTTP/1.1\r\n"
                 "Host: localhost\r\n"
                 "User-Agent: test\r\n"
@@ -319,7 +319,7 @@ public:
 
         for(n = 0; n < limit; ++n)
         {
-            test::fail_stream<test::string_stream> fs(n, ios_,
+            test::fail_stream<test::string_istream> fs(n, ios_,
                 "GET / HTTP/1.1\r\n"
                 "Host: localhost\r\n"
                 "User-Agent: test\r\n"
@@ -337,7 +337,7 @@ public:
 
         for(n = 0; n < limit; ++n)
         {
-            test::fail_stream<test::string_stream> fs(n, ios_,
+            test::fail_stream<test::string_istream> fs(n, ios_,
                 "GET / HTTP/1.1\r\n"
                 "Host: localhost\r\n"
                 "User-Agent: test\r\n"
@@ -358,7 +358,7 @@ public:
     {
         {
             streambuf sb;
-            test::string_stream ss(ios_, "");
+            test::string_istream ss(ios_, "");
             parser_v1<true, streambuf_body, fields> p;
             error_code ec;
             parse(ss, sb, p, ec);
@@ -366,7 +366,7 @@ public:
         }
         {
             streambuf sb;
-            test::string_stream ss(ios_, "");
+            test::string_istream ss(ios_, "");
             parser_v1<true, streambuf_body, fields> p;
             error_code ec;
             async_parse(ss, sb, p, do_yield[ec]);
diff --git a/test/http/streambuf_body.cpp b/test/http/streambuf_body.cpp
index 52cf2917..2b5ed5f7 100644
--- a/test/http/streambuf_body.cpp
+++ b/test/http/streambuf_body.cpp
@@ -13,7 +13,7 @@
 #include <beast/http/parser_v1.hpp>
 #include <beast/http/read.hpp>
 #include <beast/http/write.hpp>
-#include <beast/test/string_stream.hpp>
+#include <beast/test/string_istream.hpp>
 #include <beast/unit_test/suite.hpp>
 #include <boost/lexical_cast.hpp>
 
@@ -33,7 +33,7 @@ public:
             "Content-Length: 3\r\n"
             "\r\n"
             "xyz";
-        test::string_stream ss(ios_, s);
+        test::string_istream ss(ios_, s);
         parser_v1<false, streambuf_body, fields> p;
         streambuf sb;
         parse(ss, sb, p);
diff --git a/test/http/write.cpp b/test/http/write.cpp
index aa58e0bf..10eeb92c 100644
--- a/test/http/write.cpp
+++ b/test/http/write.cpp
@@ -17,6 +17,7 @@
 #include <beast/core/streambuf.hpp>
 #include <beast/core/to_string.hpp>
 #include <beast/test/fail_stream.hpp>
+#include <beast/test/string_ostream.hpp>
 #include <beast/test/yield_to.hpp>
 #include <beast/unit_test/suite.hpp>
 #include <boost/asio/error.hpp>
@@ -31,68 +32,6 @@ class write_test
     , public test::enable_yield_to
 {
 public:
-    class string_write_stream
-    {
-        boost::asio::io_service& ios_;
-
-    public:
-        std::string str;
-
-        explicit
-        string_write_stream(boost::asio::io_service& ios)
-            : ios_(ios)
-        {
-        }
-
-        boost::asio::io_service&
-        get_io_service()
-        {
-            return ios_;
-        }
-
-        template<class ConstBufferSequence>
-        std::size_t
-        write_some(ConstBufferSequence const& buffers)
-        {
-            error_code ec;
-            auto const n = write_some(buffers, ec);
-            if(ec)
-                throw system_error{ec};
-            return n;
-        }
-
-        template<class ConstBufferSequence>
-        std::size_t
-        write_some(
-            ConstBufferSequence const& buffers, error_code&)
-        {
-            auto const n = buffer_size(buffers);
-            using boost::asio::buffer_size;
-            using boost::asio::buffer_cast;
-            str.reserve(str.size() + n);
-            for(auto const& buffer : buffers)
-                str.append(buffer_cast<char const*>(buffer),
-                    buffer_size(buffer));
-            return n;
-        }
-
-        template<class ConstBufferSequence, class WriteHandler>
-        typename async_completion<
-            WriteHandler, void(error_code)>::result_type
-        async_write_some(ConstBufferSequence const& buffers,
-            WriteHandler&& handler)
-        {
-            error_code ec;
-            auto const bytes_transferred = write_some(buffers, ec);
-            async_completion<
-                WriteHandler, void(error_code, std::size_t)
-                    > completion(handler);
-            get_io_service().post(
-                bind_handler(completion.handler, ec, bytes_transferred));
-            return completion.result.get();
-        }
-    };
-
     struct unsized_body
     {
         using value_type = std::string;
@@ -225,7 +164,7 @@ public:
     std::string
     str(message<isRequest, Body, Fields> const& m)
     {
-        string_write_stream ss(ios_);
+        test::string_ostream ss(ios_);
         write(ss, m);
         return ss.str;
     }
@@ -240,7 +179,7 @@ public:
             m.url = "/";
             m.fields.insert("User-Agent", "test");
             error_code ec;
-            string_write_stream ss{ios_};
+            test::string_ostream ss{ios_};
             async_write(ss, m, do_yield[ec]);
             if(BEAST_EXPECTS(! ec, ec.message()))
                 BEAST_EXPECT(ss.str ==
@@ -256,7 +195,7 @@ public:
             m.fields.insert("Server", "test");
             m.fields.insert("Content-Length", "5");
             error_code ec;
-            string_write_stream ss{ios_};
+            test::string_ostream ss{ios_};
             async_write(ss, m, do_yield[ec]);
             if(BEAST_EXPECTS(! ec, ec.message()))
                 BEAST_EXPECT(ss.str ==
@@ -279,7 +218,7 @@ public:
             m.fields.insert("Content-Length", "5");
             m.body = "*****";
             error_code ec;
-            string_write_stream ss{ios_};
+            test::string_ostream ss{ios_};
             async_write(ss, m, do_yield[ec]);
             if(BEAST_EXPECTS(! ec, ec.message()))
                 BEAST_EXPECT(ss.str ==
@@ -298,7 +237,7 @@ public:
             m.fields.insert("Transfer-Encoding", "chunked");
             m.body = "*****";
             error_code ec;
-            string_write_stream ss(ios_);
+            test::string_ostream ss(ios_);
             async_write(ss, m, do_yield[ec]);
             if(BEAST_EXPECTS(! ec, ec.message()))
                 BEAST_EXPECT(ss.str ==
@@ -322,7 +261,7 @@ public:
         {
             test::fail_counter fc(n);
             test::fail_stream<
-                string_write_stream> fs(fc, ios_);
+                test::string_ostream> fs(fc, ios_);
             message<true, fail_body, fields> m(
                 std::piecewise_construct,
                     std::forward_as_tuple(fc, ios_));
@@ -355,7 +294,7 @@ public:
         {
             test::fail_counter fc(n);
             test::fail_stream<
-                string_write_stream> fs(fc, ios_);
+                test::string_ostream> fs(fc, ios_);
             message<true, fail_body, fields> m(
                 std::piecewise_construct,
                     std::forward_as_tuple(fc, ios_));
@@ -390,7 +329,7 @@ public:
         {
             test::fail_counter fc(n);
             test::fail_stream<
-                string_write_stream> fs(fc, ios_);
+                test::string_ostream> fs(fc, ios_);
             message<true, fail_body, fields> m(
                 std::piecewise_construct,
                     std::forward_as_tuple(fc, ios_));
@@ -425,7 +364,7 @@ public:
         {
             test::fail_counter fc(n);
             test::fail_stream<
-                string_write_stream> fs(fc, ios_);
+                test::string_ostream> fs(fc, ios_);
             message<true, fail_body, fields> m(
                 std::piecewise_construct,
                     std::forward_as_tuple(fc, ios_));
@@ -455,7 +394,7 @@ public:
         {
             test::fail_counter fc(n);
             test::fail_stream<
-                string_write_stream> fs(fc, ios_);
+                test::string_ostream> fs(fc, ios_);
             message<true, fail_body, fields> m(
                 std::piecewise_construct,
                     std::forward_as_tuple(fc, ios_));
@@ -547,7 +486,7 @@ public:
             m.fields.insert("User-Agent", "test");
             m.body = "*";
             prepare(m);
-            string_write_stream ss(ios_);
+            test::string_ostream ss(ios_);
             error_code ec;
             write(ss, m, ec);
             BEAST_EXPECT(ec == boost::asio::error::eof);
@@ -584,7 +523,7 @@ public:
             m.fields.insert("User-Agent", "test");
             m.body = "*";
             prepare(m, connection::close);
-            string_write_stream ss(ios_);
+            test::string_ostream ss(ios_);
             error_code ec;
             write(ss, m, ec);
             BEAST_EXPECT(ec == boost::asio::error::eof);
@@ -621,7 +560,7 @@ public:
             m.fields.insert("User-Agent", "test");
             m.body = "*";
             prepare(m);
-            string_write_stream ss(ios_);
+            test::string_ostream ss(ios_);
             error_code ec;
             write(ss, m, ec);
             BEAST_EXPECT(ss.str ==
diff --git a/test/websocket/stream.cpp b/test/websocket/stream.cpp
index ad1a535a..d02dd2f4 100644
--- a/test/websocket/stream.cpp
+++ b/test/websocket/stream.cpp
@@ -14,7 +14,7 @@
 #include <beast/core/streambuf.hpp>
 #include <beast/core/to_string.hpp>
 #include <beast/test/fail_stream.hpp>
-#include <beast/test/string_stream.hpp>
+#include <beast/test/string_istream.hpp>
 #include <beast/test/yield_to.hpp>
 #include <beast/unit_test/suite.hpp>
 #include <boost/asio.hpp>
@@ -172,7 +172,7 @@ public:
                 req.fields.insert("Sec-WebSocket-Key", "dGhlIHNhbXBsZSBub25jZQ==");
                 req.fields.insert("Sec-WebSocket-Version", "13");
                 stream<test::fail_stream<
-                    test::string_stream>> ws(n, ios_, "");
+                    test::string_istream>> ws(n, ios_, "");
                 try
                 {
                     ws.accept(req);
@@ -186,7 +186,7 @@ public:
         }
         {
             // valid
-            stream<test::string_stream> ws(ios_,
+            stream<test::string_istream> ws(ios_,
                 "GET / HTTP/1.1\r\n"
                 "Host: localhost:80\r\n"
                 "Upgrade: WebSocket\r\n"
@@ -207,7 +207,7 @@ public:
         }
         {
             // invalid
-            stream<test::string_stream> ws(ios_,
+            stream<test::string_istream> ws(ios_,
                 "GET / HTTP/1.0\r\n"
                 "\r\n"
             );
@@ -230,7 +230,7 @@ public:
             {
                 for(std::size_t i = 0; i < s.size(); ++i)
                 {
-                    stream<test::string_stream> ws(ios_,
+                    stream<test::string_istream> ws(ios_,
                         s.substr(i, s.size() - i));
                     ws.set_option(keep_alive{true});
                     try
@@ -339,7 +339,7 @@ public:
         auto const check =
             [&](std::string const& s)
             {
-                stream<test::string_stream> ws(ios_, s);
+                stream<test::string_istream> ws(ios_, s);
                 try
                 {
                     ws.handshake("localhost:80", "/");