diff --git a/fdbrpc/FlowTransport.actor.cpp b/fdbrpc/FlowTransport.actor.cpp
index c58321ce6e..44d0552276 100644
--- a/fdbrpc/FlowTransport.actor.cpp
+++ b/fdbrpc/FlowTransport.actor.cpp
@@ -444,7 +444,7 @@ struct Peer : NonCopyable {
 			loop {
 				lastWriteTime = now();
 
-				int sent = conn->write(self->unsent.getUnsent(), 200 * 1024);  // avoid sending large packet
+				int sent = conn->write(self->unsent.getUnsent(), /* limit= */ FLOW_KNOBS->MAX_PACKET_SEND_BYTES);
 				if (sent) {
 					self->transport->bytesSent += sent;
 					self->unsent.sent(sent);
@@ -735,14 +735,15 @@ static void scanPackets(TransportData* transport, uint8_t*& unprocessed_begin, c
 static int getNewBufferSize(uint8_t* begin, uint8_t* end, const NetworkAddress& peerAddress) {
 	const int len = end - begin;
 	if (len < sizeof(uint32_t)) {
-		return std::max(65536, len * 2);
+		return std::max(FLOW_KNOBS->DEFAULT_PACKET_BUFFER_BYTES, len * 2);
 	}
 	const uint32_t packetLen = *(uint32_t*)begin;
 	if (packetLen > FLOW_KNOBS->PACKET_LIMIT) {
 		TraceEvent(SevError, "Net2_PacketLimitExceeded").detail("FromPeer", peerAddress.toString()).detail("Length", (int)packetLen);
 		throw platform_error();
 	}
-	return std::max<uint32_t>(4096, packetLen + sizeof(uint32_t) * (peerAddress.isTLS() ? 1 : 2));
+	return std::max<uint32_t>(FLOW_KNOBS->MIN_PACKET_BUFFER_BYTES,
+	                          packetLen + sizeof(uint32_t) * (peerAddress.isTLS() ? 1 : 2));
 }
 
 ACTOR static Future<Void> connectionReader(
diff --git a/flow/Knobs.cpp b/flow/Knobs.cpp
index c8acae874f..ed1323aba3 100644
--- a/flow/Knobs.cpp
+++ b/flow/Knobs.cpp
@@ -109,6 +109,9 @@ FlowKnobs::FlowKnobs(bool randomize, bool isSimulated) {
 	init( PACKET_LIMIT,                                  100LL<<20 );
 	init( PACKET_WARNING,                                  2LL<<20 );  // 2MB packet warning quietly allows for 1MB system messages
 	init( TIME_OFFSET_LOGGING_INTERVAL,                       60.0 );
+	init( MAX_PACKET_SEND_BYTES,                        256 * 1024 );
+	init( DEFAULT_PACKET_BUFFER_BYTES,                   64 * 1024 );
+	init( MIN_PACKET_BUFFER_BYTES,                        4 * 1024 );
 
 	//Sim2
 	init( MIN_OPEN_TIME,                                    0.0002 );
diff --git a/flow/Knobs.h b/flow/Knobs.h
index 6633cda75a..0a46363d2c 100644
--- a/flow/Knobs.h
+++ b/flow/Knobs.h
@@ -128,6 +128,9 @@ public:
 	int64_t PACKET_LIMIT;
 	int64_t PACKET_WARNING;  // 2MB packet warning quietly allows for 1MB system messages
 	double TIME_OFFSET_LOGGING_INTERVAL;
+	int MAX_PACKET_SEND_BYTES;
+	int DEFAULT_PACKET_BUFFER_BYTES;
+	int MIN_PACKET_BUFFER_BYTES;
 
 	//Sim2
 	//FIMXE: more parameters could be factored out