diff --git a/NetworkWeatherService/Derivation/derivation.py b/NetworkWeatherService/Derivation/derivation.py
index e35b97b..1c9a849 100644
--- a/NetworkWeatherService/Derivation/derivation.py
+++ b/NetworkWeatherService/Derivation/derivation.py
@@ -21,7 +21,7 @@ def worker():
         lock.release()
         print "records:",res['hits']['total'], "\t remaining:",q.qsize(), "\ttotal rec:",totr
         q.task_done()
-            
+
 print "make sure we are connected right."
 import requests
 res = requests.get('http://cl-analytics.mwt2.org:9200')
@@ -33,7 +33,7 @@ def worker():
 print es.count(index="network_weather-2015-10-11")
 
 usrc={
-    "size": 0, 
+    "size": 0,
     "aggregations": {
        "unique_vals": {
           "terms": {
@@ -44,7 +44,7 @@ def worker():
     }
 }
 udest={
-    "size": 0, 
+    "size": 0,
     "aggregations": {
        "unique_vals": {
           "terms": {
@@ -113,4 +113,3 @@ def worker():
 #         print "\t delay_mean:",hit['_source']['@message']['delay_mean'], "\tdelay_sd:",hit['_source']['@message']['delay_sd']
 #     elif hit['_type']=='throughput':
 #         print "\t throughput:",hit['_source']['@message']['throughput']
-    
\ No newline at end of file
diff --git a/NetworkWeatherService/Derivation/maximum_throughput.py b/NetworkWeatherService/Derivation/maximum_throughput.py
new file mode 100644
index 0000000..2d2e1e7
--- /dev/null
+++ b/NetworkWeatherService/Derivation/maximum_throughput.py
@@ -0,0 +1,91 @@
+
+# TODO: Keep a dictionary of source-dest pairs => bools to keep track of
+# the source-dest pairs we've already computed maximum throughput for.
+
+def max_throughput(time_a, time_b, mean_packet_loss):
+    # Expected TCP segment size limit: 1500 octets
+    mean_segment_size = 1500
+    round_trip_time = time_a + time_b
+    # Formula given by https://en.wikipedia.org/wiki/TCP_tuning#Packet_loss
+    return mean_segment_size / (round_trip_time * math.sqrt(mean_packet_loss))
+
+nw_index = "network_weather-2015-10-11"
+
+def get_all_throughputs():
+    for s in usrcs:
+        for d in udests:
+            st={
+            "query": {
+                    "filtered":{
+                        "query": {
+                            "match_all": {}
+                        },
+                        "filter":{
+                            "and": [
+                                {
+                                    "term":{ "@message.src":s }
+                                },
+                                {
+                                    "term":{ "@message.dest":d }
+                                }
+                            ]
+                        }
+                    }
+                }
+            }
+
+            st_rev={
+            "query": {
+                    "filtered":{
+                        "query": {
+                            "match_all": {}
+                        },
+                        "filter":{
+                            "and": [
+                                {
+                                    "term":{ "@message.src":d }
+                                },
+                                {
+                                    "term":{ "@message.dest":s }
+                                }
+                            ]
+                        }
+                    }
+                }
+            }
+
+            res = es.search(index=nw_index, body=st, size=1000)
+            res_rev = es.search(index=nw_index, body=st_rev, size=1000)
+
+            if res and res_rev:
+                # Both source-dest and dest-source result dictionaries are nonempty
+                num_sd_delay = 0
+                tot_sd_delay = 0
+                num_ds_delay = 0
+                tot_ds_delay = 0
+                num_pl = 0
+                tot_pl = 0
+
+                # Calculate simple averages
+                for sd_hit in res['hits']['hits']:
+                    if sd_hit['_type'] == 'packet_loss_rate':
+                        num_pl += 1
+                        tot_pl += sd_hit['_source']['@message']['packet_loss']
+                    elif sd_hit['_type'] == 'latency':
+                        num_sd_delay += 1
+                        tot_sd_delay += sd_hit['_source']['@message']['delay_mean']
+
+                for ds_hit in res_rev['hits']['hits']:
+                    if ds_hit['_type'] == 'packet_loss_rate':
+                        num_pl += 1
+                        tot_pl += ds_hit['_source']['@message']['packet_loss']
+                    elif sd_hit['_type'] == 'latency':
+                        num_ds_delay += 1
+                        tot_ds_delay += ds_hit['_source']['@message']['delay_mean']
+
+                avg_sd_delay = tot_sd_delay / num_sd_delay
+                avg_ds_delay = tot_ds_delay / num_ds_delay
+                avg_pl = tot_pl / num_pl
+
+                tp = max_throughput(avg_sd_delay, avg_ds_delay, avg_pl)
+                print 'max throughput for source-destination pair (%s - %s):\t %f' % (s, d, tp)