diff --git a/Telegram/SourceFiles/mtproto/connection_abstract.h b/Telegram/SourceFiles/mtproto/connection_abstract.h
index 926c818a77..bc22a3cc97 100644
--- a/Telegram/SourceFiles/mtproto/connection_abstract.h
+++ b/Telegram/SourceFiles/mtproto/connection_abstract.h
@@ -81,7 +81,8 @@ public:
 		const QString &ip,
 		int port,
 		const bytes::vector &protocolSecret,
-		int16 protocolDcId) = 0;
+		int16 protocolDcId,
+		bool protocolForFiles) = 0;
 	virtual void timedOut() {
 	}
 	[[nodiscard]] virtual bool isConnected() const = 0;
diff --git a/Telegram/SourceFiles/mtproto/connection_http.cpp b/Telegram/SourceFiles/mtproto/connection_http.cpp
index 3417651e33..bebdb4e333 100644
--- a/Telegram/SourceFiles/mtproto/connection_http.cpp
+++ b/Telegram/SourceFiles/mtproto/connection_http.cpp
@@ -67,7 +67,8 @@ void HttpConnection::connectToServer(
 		const QString &address,
 		int port,
 		const bytes::vector &protocolSecret,
-		int16 protocolDcId) {
+		int16 protocolDcId,
+		bool protocolForFiles) {
 	_address = address;
 	connect(
 		&_manager,
diff --git a/Telegram/SourceFiles/mtproto/connection_http.h b/Telegram/SourceFiles/mtproto/connection_http.h
index 8fb867aa51..bbc7a44a76 100644
--- a/Telegram/SourceFiles/mtproto/connection_http.h
+++ b/Telegram/SourceFiles/mtproto/connection_http.h
@@ -29,7 +29,8 @@ public:
 		const QString &address,
 		int port,
 		const bytes::vector &protocolSecret,
-		int16 protocolDcId) override;
+		int16 protocolDcId,
+		bool protocolForFiles) override;
 	bool isConnected() const override;
 	bool usingHttpWait() override;
 	bool needHttpWait() override;
@@ -40,7 +41,7 @@ public:
 	QString tag() const override;
 
 	static mtpBuffer handleResponse(QNetworkReply *reply);
-	static qint32 handleError(QNetworkReply *reply); // returnes error code
+	static qint32 handleError(QNetworkReply *reply); // Returns error code.
 
 private:
 	QUrl url() const;
diff --git a/Telegram/SourceFiles/mtproto/connection_resolving.cpp b/Telegram/SourceFiles/mtproto/connection_resolving.cpp
index 392a311a36..0c3a86af83 100644
--- a/Telegram/SourceFiles/mtproto/connection_resolving.cpp
+++ b/Telegram/SourceFiles/mtproto/connection_resolving.cpp
@@ -83,7 +83,8 @@ void ResolvingConnection::setChild(ConnectionPointer &&child) {
 			_address,
 			_port,
 			_protocolSecret,
-			_protocolDcId);
+			_protocolDcId,
+			_protocolForFiles);
 	}
 }
 
@@ -218,7 +219,8 @@ void ResolvingConnection::connectToServer(
 		const QString &address,
 		int port,
 		const bytes::vector &protocolSecret,
-		int16 protocolDcId) {
+		int16 protocolDcId,
+		bool protocolForFiles) {
 	if (!_child) {
 		InvokeQueued(this, [=] { emitError(kErrorCodeOther); });
 		return;
@@ -227,6 +229,7 @@ void ResolvingConnection::connectToServer(
 	_port = port;
 	_protocolSecret = protocolSecret;
 	_protocolDcId = protocolDcId;
+	_protocolForFiles = protocolForFiles;
 	DEBUG_LOG(("Resolving Info: dc:%1 proxy '%2' connects a child '%3'").arg(
 		QString::number(_protocolDcId),
 		_proxy.host +':' + QString::number(_proxy.port),
@@ -237,7 +240,8 @@ void ResolvingConnection::connectToServer(
 		address,
 		port,
 		protocolSecret,
-		protocolDcId);
+		protocolDcId,
+		protocolForFiles);
 }
 
 bool ResolvingConnection::isConnected() const {
diff --git a/Telegram/SourceFiles/mtproto/connection_resolving.h b/Telegram/SourceFiles/mtproto/connection_resolving.h
index eeb137113c..0769a18b31 100644
--- a/Telegram/SourceFiles/mtproto/connection_resolving.h
+++ b/Telegram/SourceFiles/mtproto/connection_resolving.h
@@ -32,7 +32,8 @@ public:
 		const QString &address,
 		int port,
 		const bytes::vector &protocolSecret,
-		int16 protocolDcId) override;
+		int16 protocolDcId,
+		bool protocolForFiles) override;
 	bool isConnected() const override;
 	bool requiresExtendedPadding() const override;
 
@@ -63,6 +64,7 @@ private:
 	int _port = 0;
 	bytes::vector _protocolSecret;
 	int16 _protocolDcId = 0;
+	bool _protocolForFiles = false;
 	base::Timer _timeoutTimer;
 
 };
diff --git a/Telegram/SourceFiles/mtproto/connection_tcp.cpp b/Telegram/SourceFiles/mtproto/connection_tcp.cpp
index 06838b3a89..ea1f69f785 100644
--- a/Telegram/SourceFiles/mtproto/connection_tcp.cpp
+++ b/Telegram/SourceFiles/mtproto/connection_tcp.cpp
@@ -512,7 +512,8 @@ void TcpConnection::connectToServer(
 		const QString &address,
 		int port,
 		const bytes::vector &protocolSecret,
-		int16 protocolDcId) {
+		int16 protocolDcId,
+		bool protocolForFiles) {
 	Expects(_address.isEmpty());
 	Expects(_port == 0);
 	Expects(_protocol == nullptr);
@@ -543,7 +544,8 @@ void TcpConnection::connectToServer(
 	_socket = AbstractSocket::Create(
 		thread(),
 		secret,
-		ToNetworkProxy(_proxy));
+		ToNetworkProxy(_proxy),
+		protocolForFiles);
 	_protocolDcId = protocolDcId;
 
 	_socket->connected(
diff --git a/Telegram/SourceFiles/mtproto/connection_tcp.h b/Telegram/SourceFiles/mtproto/connection_tcp.h
index 1fc5319a1f..8698a00f8e 100644
--- a/Telegram/SourceFiles/mtproto/connection_tcp.h
+++ b/Telegram/SourceFiles/mtproto/connection_tcp.h
@@ -32,7 +32,8 @@ public:
 		const QString &address,
 		int port,
 		const bytes::vector &protocolSecret,
-		int16 protocolDcId) override;
+		int16 protocolDcId,
+		bool protocolForFiles) override;
 	void timedOut() override;
 	bool isConnected() const override;
 	bool requiresExtendedPadding() const override;
diff --git a/Telegram/SourceFiles/mtproto/details/mtproto_abstract_socket.cpp b/Telegram/SourceFiles/mtproto/details/mtproto_abstract_socket.cpp
index 2ad0a44a64..055b5c2563 100644
--- a/Telegram/SourceFiles/mtproto/details/mtproto_abstract_socket.cpp
+++ b/Telegram/SourceFiles/mtproto/details/mtproto_abstract_socket.cpp
@@ -15,11 +15,16 @@ namespace MTP::details {
 std::unique_ptr<AbstractSocket> AbstractSocket::Create(
 		not_null<QThread*> thread,
 		const bytes::vector &secret,
-		const QNetworkProxy &proxy) {
+		const QNetworkProxy &proxy,
+		bool protocolForFiles) {
 	if (secret.size() >= 21 && secret[0] == bytes::type(0xEE)) {
-		return std::make_unique<TlsSocket>(thread, secret, proxy);
+		return std::make_unique<TlsSocket>(
+			thread,
+			secret,
+			proxy,
+			protocolForFiles);
 	} else {
-		return std::make_unique<TcpSocket>(thread, proxy);
+		return std::make_unique<TcpSocket>(thread, proxy, protocolForFiles);
 	}
 }
 
diff --git a/Telegram/SourceFiles/mtproto/details/mtproto_abstract_socket.h b/Telegram/SourceFiles/mtproto/details/mtproto_abstract_socket.h
index 61da8b5e37..ce1431fff1 100644
--- a/Telegram/SourceFiles/mtproto/details/mtproto_abstract_socket.h
+++ b/Telegram/SourceFiles/mtproto/details/mtproto_abstract_socket.h
@@ -17,7 +17,8 @@ public:
 	static std::unique_ptr<AbstractSocket> Create(
 		not_null<QThread*> thread,
 		const bytes::vector &secret,
-		const QNetworkProxy &proxy);
+		const QNetworkProxy &proxy,
+		bool protocolForFiles);
 
 	explicit AbstractSocket(not_null<QThread*> thread) {
 		moveToThread(thread);
@@ -53,6 +54,9 @@ public:
 	virtual int32 debugState() = 0;
 
 protected:
+	static const int kFilesSendBufferSize = 2 * 1024 * 1024;
+	static const int kFilesReceiveBufferSize = 2 * 1024 * 1024;
+
 	rpl::event_stream<> _connected;
 	rpl::event_stream<> _disconnected;
 	rpl::event_stream<> _readyRead;
diff --git a/Telegram/SourceFiles/mtproto/details/mtproto_tcp_socket.cpp b/Telegram/SourceFiles/mtproto/details/mtproto_tcp_socket.cpp
index 7da7e6fceb..ef9f2f327d 100644
--- a/Telegram/SourceFiles/mtproto/details/mtproto_tcp_socket.cpp
+++ b/Telegram/SourceFiles/mtproto/details/mtproto_tcp_socket.cpp
@@ -12,10 +12,21 @@ https://github.com/telegramdesktop/tdesktop/blob/master/LEGAL
 
 namespace MTP::details {
 
-TcpSocket::TcpSocket(not_null<QThread*> thread, const QNetworkProxy &proxy)
+TcpSocket::TcpSocket(
+	not_null<QThread*> thread,
+	const QNetworkProxy &proxy,
+	bool protocolForFiles)
 : AbstractSocket(thread) {
 	_socket.moveToThread(thread);
 	_socket.setProxy(proxy);
+	if (protocolForFiles) {
+		_socket.setSocketOption(
+			QAbstractSocket::SendBufferSizeSocketOption,
+			kFilesSendBufferSize);
+		_socket.setSocketOption(
+			QAbstractSocket::ReceiveBufferSizeSocketOption,
+			kFilesReceiveBufferSize);
+	}
 	const auto wrap = [&](auto handler) {
 		return [=](auto &&...args) {
 			InvokeQueued(this, [=] { handler(args...); });
diff --git a/Telegram/SourceFiles/mtproto/details/mtproto_tcp_socket.h b/Telegram/SourceFiles/mtproto/details/mtproto_tcp_socket.h
index 6c8bac8829..28e3c46653 100644
--- a/Telegram/SourceFiles/mtproto/details/mtproto_tcp_socket.h
+++ b/Telegram/SourceFiles/mtproto/details/mtproto_tcp_socket.h
@@ -13,7 +13,10 @@ namespace MTP::details {
 
 class TcpSocket final : public AbstractSocket {
 public:
-	TcpSocket(not_null<QThread*> thread, const QNetworkProxy &proxy);
+	TcpSocket(
+		not_null<QThread*> thread,
+		const QNetworkProxy &proxy,
+		bool protocolForFiles);
 
 	void connectToHost(const QString &address, int port) override;
 	bool isGoodStartNonce(bytes::const_span nonce) override;
diff --git a/Telegram/SourceFiles/mtproto/details/mtproto_tls_socket.cpp b/Telegram/SourceFiles/mtproto/details/mtproto_tls_socket.cpp
index 34030993aa..962e0268bb 100644
--- a/Telegram/SourceFiles/mtproto/details/mtproto_tls_socket.cpp
+++ b/Telegram/SourceFiles/mtproto/details/mtproto_tls_socket.cpp
@@ -446,13 +446,22 @@ void ClientHelloGenerator::writeTimestamp() {
 TlsSocket::TlsSocket(
 	not_null<QThread*> thread,
 	const bytes::vector &secret,
-	const QNetworkProxy &proxy)
+	const QNetworkProxy &proxy,
+	bool protocolForFiles)
 : AbstractSocket(thread)
 , _secret(secret) {
 	Expects(_secret.size() >= 21 && _secret[0] == bytes::type(0xEE));
 
 	_socket.moveToThread(thread);
 	_socket.setProxy(proxy);
+	if (protocolForFiles) {
+		_socket.setSocketOption(
+			QAbstractSocket::SendBufferSizeSocketOption,
+			kFilesSendBufferSize);
+		_socket.setSocketOption(
+			QAbstractSocket::ReceiveBufferSizeSocketOption,
+			kFilesReceiveBufferSize);
+	}
 	const auto wrap = [&](auto handler) {
 		return [=](auto &&...args) {
 			InvokeQueued(this, [=] { handler(args...); });
diff --git a/Telegram/SourceFiles/mtproto/details/mtproto_tls_socket.h b/Telegram/SourceFiles/mtproto/details/mtproto_tls_socket.h
index 01848230a6..4bced8d752 100644
--- a/Telegram/SourceFiles/mtproto/details/mtproto_tls_socket.h
+++ b/Telegram/SourceFiles/mtproto/details/mtproto_tls_socket.h
@@ -16,7 +16,8 @@ public:
 	TlsSocket(
 		not_null<QThread*> thread,
 		const bytes::vector &secret,
-		const QNetworkProxy &proxy);
+		const QNetworkProxy &proxy,
+		bool protocolForFiles);
 
 	void connectToHost(const QString &address, int port) override;
 	bool isGoodStartNonce(bytes::const_span nonce) override;
diff --git a/Telegram/SourceFiles/mtproto/session_private.cpp b/Telegram/SourceFiles/mtproto/session_private.cpp
index f7b300a0e9..bd71d26b3f 100644
--- a/Telegram/SourceFiles/mtproto/session_private.cpp
+++ b/Telegram/SourceFiles/mtproto/session_private.cpp
@@ -226,9 +226,17 @@ void SessionPrivate::appendTestConnection(
 		});
 	});
 
+	const auto protocolForFiles = isDownloadDcId(_shiftedDcId)
+		//|| isUploadDcId(_shiftedDcId)
+		|| (_realDcType == DcType::Cdn);
 	const auto protocolDcId = getProtocolDcId();
 	InvokeQueued(_testConnections.back().data, [=] {
-		weak->connectToServer(ip, port, protocolSecret, protocolDcId);
+		weak->connectToServer(
+			ip,
+			port,
+			protocolSecret,
+			protocolDcId,
+			protocolForFiles);
 	});
 }