diff --git a/client/port.cpp b/client/port.cpp
index 8d99cfd..90992ab 100644
--- a/client/port.cpp
+++ b/client/port.cpp
@@ -19,9 +19,7 @@ along with this program.  If not, see <http://www.gnu.org/licenses/>
 
 #include "port.h"
 
-#include "fileformat.h"
-#include "pcapfileformat.h"
-#include "pdmlfileformat.h"
+#include "abstractfileformat.h"
 
 #include <QApplication>
 #include <QVariant>
@@ -228,10 +226,12 @@ void Port::updateStats(OstProto::PortStats *portStats)
 bool Port::openStreams(QString fileName, bool append, QString &error)
 {
     OstProto::StreamConfigList streams;
+    AbstractFileFormat *fmt = AbstractFileFormat::fileFormatFromFile(fileName);
 
-    //if (!fileFormat.openStreams(fileName, streams, error))
-    //if (!pdmlFileFormat.openStreams(fileName, streams, error))
-    if (!pcapFileFormat.openStreams(fileName, streams, error))
+    if (fmt == NULL)
+        goto _fail;
+
+    if (!fmt->openStreams(fileName, streams, error))
         goto _fail;
 
     if (!append)
@@ -253,10 +253,14 @@ _fail:
     return false;
 }
 
-bool Port::saveStreams(QString fileName, QString &error)
+bool Port::saveStreams(QString fileName, QString fileType, QString &error)
 {
+    AbstractFileFormat *fmt = AbstractFileFormat::fileFormatFromType(fileType);
     OstProto::StreamConfigList streams;
 
+    if (fmt == NULL)
+        goto _fail;
+
     streams.mutable_port_id()->set_id(0);
     for (int i = 0; i < mStreams.size(); i++)
     {
@@ -264,6 +268,9 @@ bool Port::saveStreams(QString fileName, QString &error)
         mStreams[i]->protoDataCopyInto(*s);
     }
 
-    //return fileFormat.saveStreams(streams, fileName, error);
-    return pcapFileFormat.saveStreams(streams, fileName, error);
+    return fmt->saveStreams(streams, fileName, error);
+
+_fail:
+    error = QString("Unsupported File Type - %1").arg(fileType);
+    return false;
 }
diff --git a/client/port.h b/client/port.h
index 2fbb9a0..275ea61 100644
--- a/client/port.h
+++ b/client/port.h
@@ -119,7 +119,7 @@ public:
     void updateStats(OstProto::PortStats *portStats);
 
     bool openStreams(QString fileName, bool append, QString &error);
-    bool saveStreams(QString fileName, QString &error);
+    bool saveStreams(QString fileName, QString fileType, QString &error);
 
 signals:
     void portDataChanged(int portGroupId, int portId);
diff --git a/client/portswindow.cpp b/client/portswindow.cpp
index 58070a0..86bcf71 100644
--- a/client/portswindow.cpp
+++ b/client/portswindow.cpp
@@ -19,13 +19,14 @@ along with this program.  If not, see <http://www.gnu.org/licenses/>
 
 #include "portswindow.h"
 
+#include "abstractfileformat.h"
+#include "streamconfigdialog.h"
+#include "streamlistdelegate.h"
+
 #include <QInputDialog>
 #include <QItemSelectionModel>
 #include <QMessageBox>
 
-#include "streamconfigdialog.h"
-#include "streamlistdelegate.h"
-
 PortsWindow::PortsWindow(PortGroupList *pgl, QWidget *parent)
     : QWidget(parent)
 {
@@ -497,17 +498,44 @@ void PortsWindow::on_actionSave_Streams_triggered()
 
     QModelIndex current = tvPortList->selectionModel()->currentIndex();
     QString fileName;
+    QStringList fileTypes = AbstractFileFormat::supportedFileTypes();
+    QString fileType;
     QString errorStr;
+    QFileDialog::Options options;
+
+    // On Mac OS with Native Dialog, getSaveFileName() ignores fileType 
+    // which we need.
+#ifdef Q_OS_MAC
+    options |= QFileDialog::DontUseNativeDialog;
+#endif
+
+    if (fileTypes.size())
+        fileType = fileTypes.at(0);
 
     Q_ASSERT(plm->isPort(current));
 
-    fileName = QFileDialog::getSaveFileName(this, tr("Save Streams"));
+_retry:
+    fileName = QFileDialog::getSaveFileName(this, tr("Save Streams"),
+            fileName, fileTypes.join(";;"), &fileType, options);
     if (fileName.isEmpty())
         goto _exit;
 
+    fileType = fileType.remove(QRegExp("\\(.*\\)")).trimmed();
+    if (!fileType.startsWith("Ostinato"))
+    {
+        if (QMessageBox::warning(this, tr("Ostinato"), 
+            QString("You have chosen to save in %1 format. All stream "
+                "attributes may not be saved in this format.\n\n"
+                "It is recommended to save in native Ostinato format.\n\n"
+                "Continue to save in %2 format?").arg(fileType).arg(fileType),
+            QMessageBox::Yes|QMessageBox::No,
+            QMessageBox::No) != QMessageBox::Yes)
+            goto _retry;
+    }
+
     // TODO: all or selected?
 
-    if (!plm->port(current).saveStreams(fileName, errorStr))
+    if (!plm->port(current).saveStreams(fileName, fileType, errorStr))
         QMessageBox::critical(this, qApp->applicationName(), errorStr);
     else if (!errorStr.isEmpty())
         QMessageBox::warning(this, qApp->applicationName(), errorStr);
diff --git a/common/abstractfileformat.cpp b/common/abstractfileformat.cpp
new file mode 100644
index 0000000..cb3fa43
--- /dev/null
+++ b/common/abstractfileformat.cpp
@@ -0,0 +1,73 @@
+/*
+Copyright (C) 2011 Srivats P.
+
+This file is part of "Ostinato"
+
+This is free software: you can redistribute it and/or modify
+it under the terms of the GNU General Public License as published by
+the Free Software Foundation, either version 3 of the License, or
+(at your option) any later version.
+
+This program is distributed in the hope that it will be useful,
+but WITHOUT ANY WARRANTY; without even the implied warranty of
+MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+GNU General Public License for more details.
+
+You should have received a copy of the GNU General Public License
+along with this program.  If not, see <http://www.gnu.org/licenses/>
+*/
+
+#include "abstractfileformat.h"
+
+#include "fileformat.h"
+#include "pcapfileformat.h"
+#include "pdmlfileformat.h"
+
+#include <QStringList>
+
+AbstractFileFormat::AbstractFileFormat()
+{
+}
+
+AbstractFileFormat::~AbstractFileFormat()
+{
+}
+
+QStringList AbstractFileFormat::supportedFileTypes()
+{
+    return QStringList()
+        << "Ostinato (*)"
+        << "PCAP (*)"
+        << "PDML (*.pdml)";
+}
+AbstractFileFormat* AbstractFileFormat::fileFormatFromFile(
+        const QString fileName)
+{
+
+    if (fileFormat.isMyFileFormat(fileName))
+        return &fileFormat;
+
+    if (pdmlFileFormat.isMyFileFormat(fileName))
+        return &pdmlFileFormat;
+
+    if (pcapFileFormat.isMyFileFormat(fileName))
+        return &pcapFileFormat;
+
+    return NULL;
+}
+
+AbstractFileFormat* AbstractFileFormat::fileFormatFromType(
+        const QString fileType)
+{
+
+    if (fileFormat.isMyFileType(fileType))
+        return &fileFormat;
+
+    if (pdmlFileFormat.isMyFileType(fileType))
+        return &pdmlFileFormat;
+
+    if (pcapFileFormat.isMyFileType(fileType))
+        return &pcapFileFormat;
+
+    return NULL;
+}
diff --git a/common/abstractfileformat.h b/common/abstractfileformat.h
new file mode 100644
index 0000000..7a648ee
--- /dev/null
+++ b/common/abstractfileformat.h
@@ -0,0 +1,52 @@
+/*
+Copyright (C) 2011 Srivats P.
+
+This file is part of "Ostinato"
+
+This is free software: you can redistribute it and/or modify
+it under the terms of the GNU General Public License as published by
+the Free Software Foundation, either version 3 of the License, or
+(at your option) any later version.
+
+This program is distributed in the hope that it will be useful,
+but WITHOUT ANY WARRANTY; without even the implied warranty of
+MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+GNU General Public License for more details.
+
+You should have received a copy of the GNU General Public License
+along with this program.  If not, see <http://www.gnu.org/licenses/>
+*/
+
+#ifndef _ABSTRACT_FILE_FORMAT_H
+#define _ABSTRACT_FILE_FORMAT_H
+
+#include "protocol.pb.h"
+
+#include <QObject>
+#include <QString>
+
+class AbstractFileFormat : public QObject
+{
+    Q_OBJECT 
+public:
+    AbstractFileFormat();
+    virtual ~AbstractFileFormat();
+
+    virtual bool openStreams(const QString fileName, 
+            OstProto::StreamConfigList &streams, QString &error) = 0;
+    virtual bool saveStreams(const OstProto::StreamConfigList streams, 
+            const QString fileName, QString &error) = 0;
+
+    static AbstractFileFormat* fileFormatFromFile(const QString fileName);
+    static AbstractFileFormat* fileFormatFromType(const QString fileType);
+
+    static QStringList supportedFileTypes();
+
+#if 0
+    bool isMyFileFormat(const QString fileName) = 0;
+    bool isMyFileType(const QString fileType) = 0;
+#endif
+};
+
+#endif
+
diff --git a/common/fileformat.cpp b/common/fileformat.cpp
index 619ab37..7ddc65b 100644
--- a/common/fileformat.cpp
+++ b/common/fileformat.cpp
@@ -394,6 +394,38 @@ _fail:
     return false;
 }
 
+bool FileFormat::isMyFileFormat(const QString fileName)
+{
+    bool ret = false;
+    QFile file(fileName);
+    QByteArray buf;
+    OstProto::FileMagic magic;
+
+    if (!file.open(QIODevice::ReadOnly))
+        goto _exit;
+
+    buf = file.peek(kFileMagicOffset + kFileMagicSize);
+    if (!magic.ParseFromArray((void*)(buf.constData() + kFileMagicOffset), 
+                kFileMagicSize))
+        goto _close_exit;
+
+    if (magic.value() == kFileMagicValue)
+        ret = true;
+
+_close_exit:
+    file.close();
+_exit:
+    return ret;
+}
+
+bool FileFormat::isMyFileType(const QString fileType)
+{
+    if (fileType.startsWith("Ostinato"))
+        return true;
+    else
+        return false;
+}
+
 void FileFormat::initFileMetaData(OstProto::FileMetaData &metaData)
 {
     // Fill in the "native" file format version
diff --git a/common/fileformat.h b/common/fileformat.h
index ebdc97c..0204906 100644
--- a/common/fileformat.h
+++ b/common/fileformat.h
@@ -19,24 +19,27 @@ along with this program.  If not, see <http://www.gnu.org/licenses/>
 #ifndef _FILE_FORMAT_H
 #define _FILE_FORMAT_H
 
+#include "abstractfileformat.h"
+
 #include "fileformat.pb.h"
 
-#include <QString>
-#include <QObject>
-
-class FileFormat : public QObject
+class FileFormat : public AbstractFileFormat
 {
-    Q_OBJECT 
 public:
     FileFormat();
     ~FileFormat();
 
-    bool openStreams(const QString fileName, 
+    virtual bool openStreams(const QString fileName, 
             OstProto::StreamConfigList &streams, QString &error);
-    bool saveStreams(const OstProto::StreamConfigList streams, 
+    virtual bool saveStreams(const OstProto::StreamConfigList streams, 
             const QString fileName, QString &error);
 
+    bool isMyFileFormat(const QString fileName);
+    bool isMyFileType(const QString fileType);
+
 private:
+    void initFileMetaData(OstProto::FileMetaData &metaData);
+
     static const int kFileMagicSize = 12;
     static const int kFileChecksumSize = 5;
     static const int kFileMinSize = kFileMagicSize + kFileChecksumSize;
@@ -50,8 +53,6 @@ private:
     static const uint kFileFormatVersionMajor = 0;
     static const uint kFileFormatVersionMinor = 1;
     static const uint kFileFormatVersionRevision = 3;
-
-    void initFileMetaData(OstProto::FileMetaData &metaData);
 };
 
 extern FileFormat fileFormat;
diff --git a/common/ostproto.pro b/common/ostproto.pro
index ef829da..3283090 100644
--- a/common/ostproto.pro
+++ b/common/ostproto.pro
@@ -57,6 +57,7 @@ PROTOS += \
 HEADERS += \
     abstractprotocol.h    \
     comboprotocol.h    \
+    abstractfileformat.h \
     fileformat.h \
     pcapfileformat.h \
     pdmlfileformat.h \
@@ -98,6 +99,7 @@ HEADERS += \
 SOURCES += \
     abstractprotocol.cpp \
     crc32c.cpp \
+    abstractfileformat.cpp \
     fileformat.cpp \
     pcapfileformat.cpp \
     pdmlfileformat.cpp \
diff --git a/common/pcapfileformat.cpp b/common/pcapfileformat.cpp
index 967c565..a893565 100644
--- a/common/pcapfileformat.cpp
+++ b/common/pcapfileformat.cpp
@@ -25,6 +25,7 @@ along with this program.  If not, see <http://www.gnu.org/licenses/>
 
 #include <QDataStream>
 #include <QFile>
+#include <QFileInfo>
 #include <QProcess>
 #include <QTemporaryFile>
 #include <QtGlobal>
@@ -243,7 +244,7 @@ _non_pdml:
 _err_unsupported_encap:
     error = QString(tr("%1 has non-ethernet encapsulation (%2) which is "
                 "not supported - Sorry!"))
-            .arg(fileName).arg(fileHdr.network);
+            .arg(QFileInfo(fileName).fileName()).arg(fileHdr.network);
     goto _exit;
 #endif
 
@@ -391,3 +392,16 @@ _exit:
     return isOk;
 }
 
+bool PcapFileFormat::isMyFileFormat(const QString fileName)
+{
+    // TODO
+    return true;
+}
+
+bool PcapFileFormat::isMyFileType(const QString fileType)
+{
+    if (fileType.startsWith("PCAP"))
+        return true;
+    else
+        return false;
+}
diff --git a/common/pcapfileformat.h b/common/pcapfileformat.h
index 04a02ec..4f7ab7a 100644
--- a/common/pcapfileformat.h
+++ b/common/pcapfileformat.h
@@ -19,16 +19,13 @@ along with this program.  If not, see <http://www.gnu.org/licenses/>
 #ifndef _PCAP_FILE_FORMAT_H
 #define _PCAP_FILE_FORMAT_H
 
-#include "protocol.pb.h"
+#include "abstractfileformat.h"
 
 #include <QDataStream>
-#include <QObject>
 
 class PdmlReader;
-class PcapFileFormat : public QObject
+class PcapFileFormat : public AbstractFileFormat
 {
-    Q_OBJECT
-
     friend class PdmlReader;
 
 public:
@@ -40,6 +37,9 @@ public:
     bool saveStreams(const OstProto::StreamConfigList streams, 
             const QString fileName, QString &error);
 
+    bool isMyFileFormat(const QString fileName);
+    bool isMyFileType(const QString fileType);
+
 private:
     typedef struct {
         quint32 magicNumber;   /* magic number */
diff --git a/common/pdmlfileformat.cpp b/common/pdmlfileformat.cpp
index 3f86084..0c51652 100644
--- a/common/pdmlfileformat.cpp
+++ b/common/pdmlfileformat.cpp
@@ -92,6 +92,43 @@ _exit:
 bool PdmlFileFormat::saveStreams(const OstProto::StreamConfigList streams, 
         const QString fileName, QString &error)
 {
+    error = "Save to PDML format is not supported";
     return false;
 }
 
+bool PdmlFileFormat::isMyFileFormat(const QString fileName)
+{
+    bool ret = false;
+    QFile file(fileName);
+    QByteArray buf;
+    QXmlStreamReader xml;
+
+    if (!file.open(QIODevice::ReadOnly))
+        goto _exit;
+
+    xml.setDevice(&file);
+
+    xml.readNext();
+    if (xml.hasError() || !xml.isStartDocument())
+        goto _close_exit;
+
+    xml.readNext();
+    if (!xml.hasError() && xml.isStartElement() && (xml.name() == "pdml"))
+        ret = true;
+    else
+        ret = false;
+
+_close_exit:
+    xml.clear();
+    file.close();
+_exit:
+    return ret;
+}
+
+bool PdmlFileFormat::isMyFileType(const QString fileType)
+{
+    if (fileType.startsWith("PDML"))
+        return true;
+    else
+        return false;
+}
diff --git a/common/pdmlfileformat.h b/common/pdmlfileformat.h
index d392c6b..e05026a 100644
--- a/common/pdmlfileformat.h
+++ b/common/pdmlfileformat.h
@@ -19,24 +19,22 @@ along with this program.  If not, see <http://www.gnu.org/licenses/>
 #ifndef _PDML_FILE_FORMAT_H
 #define _PDML_FILE_FORMAT_H
 
-#include "protocol.pb.h"
+#include "abstractfileformat.h"
 
-#include <QObject>
-
-class PdmlParser;
-
-class PdmlFileFormat : public QObject
+class PdmlFileFormat : public AbstractFileFormat
 {
-    Q_OBJECT
-
 public:
     PdmlFileFormat();
     ~PdmlFileFormat();
 
-    bool openStreams(const QString fileName, 
+    virtual bool openStreams(const QString fileName, 
             OstProto::StreamConfigList &streams, QString &error);
-    bool saveStreams(const OstProto::StreamConfigList streams, 
+    virtual bool saveStreams(const OstProto::StreamConfigList streams, 
             const QString fileName, QString &error);
+
+    bool isMyFileFormat(const QString fileName);
+    bool isMyFileType(const QString fileType);
+
 };
 
 extern PdmlFileFormat pdmlFileFormat;