diff -r 31a963b3a048 -r c255d8f54fea src/mem/ruby/network/BasicRouter.py
--- a/src/mem/ruby/network/BasicRouter.py	Wed Aug 24 11:22:26 2016 -0400
+++ b/src/mem/ruby/network/BasicRouter.py	Wed Aug 24 11:22:48 2016 -0400
@@ -34,3 +34,4 @@
     type = 'BasicRouter'
     cxx_header = "mem/ruby/network/BasicRouter.hh"
     router_id = Param.Int("ID in relation to other routers")
+    latency   = Param.Cycles(1, "number of cycles inside router")
diff -r 31a963b3a048 -r c255d8f54fea src/mem/ruby/network/Network.hh
--- a/src/mem/ruby/network/Network.hh	Wed Aug 24 11:22:26 2016 -0400
+++ b/src/mem/ruby/network/Network.hh	Wed Aug 24 11:22:48 2016 -0400
@@ -85,7 +85,9 @@
     virtual void makeExtInLink(NodeID src, SwitchID dest, BasicLink* link,
                             const NetDest& routing_table_entry) = 0;
     virtual void makeInternalLink(SwitchID src, SwitchID dest, BasicLink* link,
-                                  const NetDest& routing_table_entry) = 0;
+                                  const NetDest& routing_table_entry,
+                                  PortDirection src_outport,
+                                  PortDirection dst_inport) = 0;
 
     virtual void collateStats() = 0;
     virtual void print(std::ostream& out) const = 0;
diff -r 31a963b3a048 -r c255d8f54fea src/mem/ruby/network/Topology.hh
--- a/src/mem/ruby/network/Topology.hh	Wed Aug 24 11:22:26 2016 -0400
+++ b/src/mem/ruby/network/Topology.hh	Wed Aug 24 11:22:48 2016 -0400
@@ -52,11 +52,14 @@
 class Network;
 
 typedef std::vector<std::vector<int> > Matrix;
+typedef std::string PortDirection;
 
 struct LinkEntry
 {
     BasicLink *link;
     LinkDirection direction;
+    PortDirection src_outport_dirn;
+    PortDirection dst_inport_dirn;
 };
 
 typedef std::map<std::pair<SwitchID, SwitchID>, LinkEntry> LinkMap;
@@ -72,7 +75,9 @@
     void print(std::ostream& out) const { out << "[Topology]"; }
 
   private:
-    void addLink(SwitchID src, SwitchID dest, BasicLink* link);
+    void addLink(SwitchID src, SwitchID dest, BasicLink* link,
+                 PortDirection src_outport_dirn = "",
+                 PortDirection dest_inport_dirn = "");
     void makeLink(Network *net, SwitchID src, SwitchID dest,
                   const NetDest& routing_table_entry);
 
diff -r 31a963b3a048 -r c255d8f54fea src/mem/ruby/network/Topology.cc
--- a/src/mem/ruby/network/Topology.cc	Wed Aug 24 11:22:26 2016 -0400
+++ b/src/mem/ruby/network/Topology.cc	Wed Aug 24 11:22:48 2016 -0400
@@ -88,6 +88,9 @@
         BasicRouter *router_src = int_link->params()->src_node;
         BasicRouter *router_dst = int_link->params()->dst_node;
 
+        PortDirection src_outport = int_link->params()->src_outport;
+        PortDirection dst_inport = int_link->params()->dst_inport;
+
         // Store the IntLink pointers for later
         m_int_link_vector.push_back(int_link);
 
@@ -95,7 +98,7 @@
         int dst = router_dst->params()->router_id + 2*m_nodes;
 
         // create the internal uni-directional link from src to dst
-        addLink(src, dst, int_link);
+        addLink(src, dst, int_link, src_outport, dst_inport);
     }
 }
 
@@ -153,7 +156,9 @@
 }
 
 void
-Topology::addLink(SwitchID src, SwitchID dest, BasicLink* link)
+Topology::addLink(SwitchID src, SwitchID dest, BasicLink* link,
+                  PortDirection src_outport_dirn,
+                  PortDirection dst_inport_dirn)
 {
     assert(src <= m_number_of_switches+m_nodes+m_nodes);
     assert(dest <= m_number_of_switches+m_nodes+m_nodes);
@@ -164,6 +169,8 @@
     src_dest_pair.first = src;
     src_dest_pair.second = dest;
     link_entry.link = link;
+    link_entry.src_outport_dirn = src_outport_dirn;
+    link_entry.dst_inport_dirn  = dst_inport_dirn;
     m_link_map[src_dest_pair] = link_entry;
 }
 
@@ -199,7 +206,9 @@
         link_entry = m_link_map[src_dest];
         net->makeInternalLink(src - (2 * m_nodes), dest - (2 * m_nodes),
                               link_entry.link,
-                              routing_table_entry);
+                              routing_table_entry,
+                              link_entry.src_outport_dirn,
+                              link_entry.dst_inport_dirn);
     }
 }
 
diff -r 31a963b3a048 -r c255d8f54fea src/mem/ruby/network/garnet/fixed-pipeline/GarnetNetwork_d.hh
--- a/src/mem/ruby/network/garnet/fixed-pipeline/GarnetNetwork_d.hh	Wed Aug 24 11:22:26 2016 -0400
+++ b/src/mem/ruby/network/garnet/fixed-pipeline/GarnetNetwork_d.hh	Wed Aug 24 11:22:48 2016 -0400
@@ -74,7 +74,9 @@
     void makeExtInLink(NodeID src, SwitchID dest, BasicLink* link,
                     const NetDest& routing_table_entry);
     void makeInternalLink(SwitchID src, SwitchID dest, BasicLink* link,
-                          const NetDest& routing_table_entry);
+                          const NetDest& routing_table_entry,
+                          PortDirection src_outport,
+                          PortDirection dst_inport);
 
     //! Function for performing a functional write. The return value
     //! indicates the number of messages that were written.
diff -r 31a963b3a048 -r c255d8f54fea src/mem/ruby/network/garnet/fixed-pipeline/GarnetNetwork_d.cc
--- a/src/mem/ruby/network/garnet/fixed-pipeline/GarnetNetwork_d.cc	Wed Aug 24 11:22:26 2016 -0400
+++ b/src/mem/ruby/network/garnet/fixed-pipeline/GarnetNetwork_d.cc	Wed Aug 24 11:22:48 2016 -0400
@@ -175,7 +175,9 @@
 
 void
 GarnetNetwork_d::makeInternalLink(SwitchID src, SwitchID dest, BasicLink* link,
-                                  const NetDest& routing_table_entry)
+                                  const NetDest& routing_table_entry,
+                                  PortDirection src_outport,
+                                  PortDirection dst_inport)
 {
     GarnetIntLink_d* garnet_link = safe_cast<GarnetIntLink_d*>(link);
     NetworkLink_d* net_link = garnet_link->m_network_links[0];
diff -r 31a963b3a048 -r c255d8f54fea src/mem/ruby/network/garnet/flexible-pipeline/GarnetNetwork.hh
--- a/src/mem/ruby/network/garnet/flexible-pipeline/GarnetNetwork.hh	Wed Aug 24 11:22:26 2016 -0400
+++ b/src/mem/ruby/network/garnet/flexible-pipeline/GarnetNetwork.hh	Wed Aug 24 11:22:48 2016 -0400
@@ -65,7 +65,9 @@
     void makeExtInLink(NodeID src, SwitchID dest, BasicLink* link,
                     const NetDest& routing_table_entry);
     void makeInternalLink(SwitchID src, SwitchID dest, BasicLink* link,
-                          const NetDest& routing_table_entry);
+                          const NetDest& routing_table_entry,
+                          PortDirection src_outport,
+                          PortDirection dst_inport);
 
     //! Function for performing a functional read. The return value
     //! indicates if a message was found that had the required address.
diff -r 31a963b3a048 -r c255d8f54fea src/mem/ruby/network/garnet/flexible-pipeline/GarnetNetwork.cc
--- a/src/mem/ruby/network/garnet/flexible-pipeline/GarnetNetwork.cc	Wed Aug 24 11:22:26 2016 -0400
+++ b/src/mem/ruby/network/garnet/flexible-pipeline/GarnetNetwork.cc	Wed Aug 24 11:22:48 2016 -0400
@@ -128,7 +128,9 @@
 
 void
 GarnetNetwork::makeInternalLink(SwitchID src, SwitchID dest, BasicLink* link,
-                                const NetDest& routing_table_entry)
+                                const NetDest& routing_table_entry,
+                                PortDirection src_outport,
+                                PortDirection dst_inport)
 {
     GarnetIntLink* garnet_link = safe_cast<GarnetIntLink*>(link);
     NetworkLink *net_link = garnet_link->m_network_links[0];
diff -r 31a963b3a048 -r c255d8f54fea src/mem/ruby/network/simple/SimpleNetwork.hh
--- a/src/mem/ruby/network/simple/SimpleNetwork.hh	Wed Aug 24 11:22:26 2016 -0400
+++ b/src/mem/ruby/network/simple/SimpleNetwork.hh	Wed Aug 24 11:22:48 2016 -0400
@@ -64,7 +64,9 @@
     void makeExtInLink(NodeID src, SwitchID dest, BasicLink* link,
                     const NetDest& routing_table_entry);
     void makeInternalLink(SwitchID src, SwitchID dest, BasicLink* link,
-                          const NetDest& routing_table_entry);
+                          const NetDest& routing_table_entry,
+                          PortDirection src_outport,
+                          PortDirection dst_inport);
 
     void print(std::ostream& out) const;
 
diff -r 31a963b3a048 -r c255d8f54fea src/mem/ruby/network/simple/SimpleNetwork.cc
--- a/src/mem/ruby/network/simple/SimpleNetwork.cc	Wed Aug 24 11:22:26 2016 -0400
+++ b/src/mem/ruby/network/simple/SimpleNetwork.cc	Wed Aug 24 11:22:48 2016 -0400
@@ -104,7 +104,9 @@
 // From a switch to a switch
 void
 SimpleNetwork::makeInternalLink(SwitchID src, SwitchID dest, BasicLink* link,
-                                const NetDest& routing_table_entry)
+                                const NetDest& routing_table_entry,
+                                PortDirection src_outport,
+                                PortDirection dst_inport)
 {
     // Create a set of new MessageBuffers
     std::vector<MessageBuffer*> queues(m_virtual_networks);
diff -r 31a963b3a048 -r c255d8f54fea configs/topologies/Mesh_XY.py
--- a/configs/topologies/Mesh_XY.py	Wed Aug 24 11:22:26 2016 -0400
+++ b/configs/topologies/Mesh_XY.py	Wed Aug 24 11:22:48 2016 -0400
@@ -108,6 +108,8 @@
                     int_links.append(IntLink(link_id=link_count,
                                              src_node=routers[east_out],
                                              dst_node=routers[west_in],
+                                             src_outport="East",
+                                             dst_inport="West",
                                              weight=1))
                     link_count += 1
 
@@ -120,6 +122,8 @@
                     int_links.append(IntLink(link_id=link_count,
                                              src_node=routers[west_out],
                                              dst_node=routers[east_in],
+                                             src_outport="West",
+                                             dst_inport="East",
                                              weight=1))
                     link_count += 1
 
@@ -132,6 +136,8 @@
                     int_links.append(IntLink(link_id=link_count,
                                              src_node=routers[north_out],
                                              dst_node=routers[south_in],
+                                             src_outport="North",
+                                             dst_inport="South",
                                              weight=2))
                     link_count += 1
 
@@ -144,6 +150,8 @@
                     int_links.append(IntLink(link_id=link_count,
                                              src_node=routers[south_out],
                                              dst_node=routers[north_in],
+                                             src_outport="South",
+                                             dst_inport="North",
                                              weight=2))
                     link_count += 1
 
diff -r 31a963b3a048 -r c255d8f54fea src/mem/ruby/network/BasicLink.py
--- a/src/mem/ruby/network/BasicLink.py	Wed Aug 24 11:22:26 2016 -0400
+++ b/src/mem/ruby/network/BasicLink.py	Wed Aug 24 11:22:48 2016 -0400
@@ -46,11 +46,17 @@
     cxx_header = "mem/ruby/network/BasicLink.hh"
     ext_node = Param.RubyController("External node")
     int_node = Param.BasicRouter("ID of internal node")
-    bandwidth_factor = 16
+    bandwidth_factor = 16 # only used by simple network
 
 class BasicIntLink(BasicLink):
     type = 'BasicIntLink'
     cxx_header = "mem/ruby/network/BasicLink.hh"
     src_node = Param.BasicRouter("Router on src end")
     dst_node = Param.BasicRouter("Router on dst end")
+
+    # only used by Garnet.
+    src_outport = Param.String("", "Outport direction at src router")
+    dst_inport = Param.String("", "Inport direction at dst router")
+
+    # only used by simple network
     bandwidth_factor = 16
diff -r 31a963b3a048 -r c255d8f54fea src/mem/ruby/network/BasicRouter.hh
--- a/src/mem/ruby/network/BasicRouter.hh	Wed Aug 24 11:22:26 2016 -0400
+++ b/src/mem/ruby/network/BasicRouter.hh	Wed Aug 24 11:22:48 2016 -0400
@@ -51,6 +51,7 @@
     // ID in relation to other routers in the system
     //
     uint32_t m_id;
+    uint32_t m_latency;
 };
 
 inline std::ostream&
diff -r 31a963b3a048 -r c255d8f54fea src/mem/ruby/network/BasicRouter.cc
--- a/src/mem/ruby/network/BasicRouter.cc	Wed Aug 24 11:22:26 2016 -0400
+++ b/src/mem/ruby/network/BasicRouter.cc	Wed Aug 24 11:22:48 2016 -0400
@@ -32,6 +32,7 @@
     : ClockedObject(p)
 {
     m_id = p->router_id;
+    m_latency = p->latency;
 }
 
 void