diff --git a/lib/build-graph.js b/lib/build-graph.js
index e57fcf8..cd91e8e 100644
--- a/lib/build-graph.js
+++ b/lib/build-graph.js
@@ -40,20 +40,22 @@ function handleEdgeStmt(g, stmt, defaultStack, sg) {
     handleStmt(g, elem, defaultStack, sg);
 
     switch(elem.type) {
-      case "node": curr = [elem.id]; break;
-      case "subgraph": curr = collectNodeIds(elem); break;
+      case "node": curr = [elem]; break;
+      case "subgraph": curr = collectNodes(elem); break;
     }
 
     _.each(prev, function(v) {
       _.each(curr, function(w) {
         var name;
-        if (g.hasEdge(v, w) && g.isMultigraph()) {
+        if (g.hasEdge(v.id, w.id) && g.isMultigraph()) {
           name = _.uniqueId("edge");
         }
-        if (!g.hasEdge(v, w, name)) {
-          g.setEdge(v, w, _.clone(_.last(defaultStack).edge), name);
+        if (!g.hasEdge(v.id, w.id, name)) {
+          g.setEdge(v.id, w.id, _.clone(_.last(defaultStack).edge), name);
         }
-        _.merge(g.edge(v, w, name), attrs);
+        if (v.port) { _.merge(g.edge(v.id, w.id, name), { $out: v.port }); }
+        if (w.port) { _.merge(g.edge(v.id, w.id, name), { $in: w.port }); }
+        _.merge(g.edge(v.id, w.id, name), attrs);
       });
     });
 
@@ -107,8 +109,8 @@ function maybeCreateNode(g, v, defaultStack, sg) {
 }
 
 // Collect all nodes involved in a subgraph statement
-function collectNodeIds(stmt) {
-  var ids = {},
+function collectNodes(stmt) {
+  var nodes = [],
       stack = [],
       curr;
 
@@ -118,12 +120,12 @@ function collectNodeIds(stmt) {
   while(stack.length) {
     curr = stack.pop();
     switch(curr.type) {
-      case "node": ids[curr.id] = true; break;
+      case "node": nodes.push(curr); break;
       case "edge": _.each(curr.elems, push); break;
       case "subgraph": _.each(curr.stmts, push); break;
     }
   }
 
-  return _.keys(ids);
+  return _.uniq(nodes);
 }
 
diff --git a/lib/dot-grammar.js b/lib/dot-grammar.js
index 6a6c9e0..5430759 100644
--- a/lib/dot-grammar.js
+++ b/lib/dot-grammar.js
@@ -61,7 +61,7 @@ module.exports = (function() {
               attrs[k] = v;
               return { type: "inlineAttr", attrs: attrs };
             },
-        peg$c15 = function(id, attrs) { return {type: "node", id: id, attrs: attrs || {}}; },
+        peg$c15 = function(nodeId, attrs) { return {type: "node", id: nodeId.id, port: nodeId.port, attrs: attrs || {}}; },
         peg$c16 = function(lhs, rhs, attrs) {
               var elems = [lhs];
               for (var i = 0; i < rhs.length; ++i) {
@@ -114,91 +114,95 @@ module.exports = (function() {
               result[k] = v[3];
               return result;
             },
-        peg$c35 = function(id) { return { type: "node", id: id, attrs: {} }; },
-        peg$c36 = function(id) { return id; },
+        peg$c35 = function(nodeId) {
+            var attrs = {}
+            return { type: "node", id: nodeId.id, port: nodeId.port, attrs: attrs };
+          },
+        peg$c36 = function(id, port) { return { id: id, port: port }; },
         peg$c37 = ":",
         peg$c38 = { type: "literal", value: ":", description: "\":\"" },
-        peg$c39 = "ne",
-        peg$c40 = { type: "literal", value: "ne", description: "\"ne\"" },
-        peg$c41 = "se",
-        peg$c42 = { type: "literal", value: "se", description: "\"se\"" },
-        peg$c43 = "sw",
-        peg$c44 = { type: "literal", value: "sw", description: "\"sw\"" },
-        peg$c45 = "nw",
-        peg$c46 = { type: "literal", value: "nw", description: "\"nw\"" },
-        peg$c47 = "n",
-        peg$c48 = { type: "literal", value: "n", description: "\"n\"" },
-        peg$c49 = "e",
-        peg$c50 = { type: "literal", value: "e", description: "\"e\"" },
-        peg$c51 = "s",
-        peg$c52 = { type: "literal", value: "s", description: "\"s\"" },
-        peg$c53 = "w",
-        peg$c54 = { type: "literal", value: "w", description: "\"w\"" },
-        peg$c55 = "c",
-        peg$c56 = { type: "literal", value: "c", description: "\"c\"" },
-        peg$c57 = "_",
-        peg$c58 = { type: "literal", value: "_", description: "\"_\"" },
-        peg$c59 = { type: "other", description: "identifier" },
-        peg$c60 = /^[a-zA-Z\u0200-\u0377_]/,
-        peg$c61 = { type: "class", value: "[a-zA-Z\\u0200-\\u0377_]", description: "[a-zA-Z\\u0200-\\u0377_]" },
-        peg$c62 = /^[a-zA-Z\u0200-\u0377_0-9]/,
-        peg$c63 = { type: "class", value: "[a-zA-Z\\u0200-\\u0377_0-9]", description: "[a-zA-Z\\u0200-\\u0377_0-9]" },
-        peg$c64 = function(fst, rest) { return fst + rest.join(""); },
-        peg$c65 = "-",
-        peg$c66 = { type: "literal", value: "-", description: "\"-\"" },
-        peg$c67 = ".",
-        peg$c68 = { type: "literal", value: ".", description: "\".\"" },
-        peg$c69 = /^[0-9]/,
-        peg$c70 = { type: "class", value: "[0-9]", description: "[0-9]" },
-        peg$c71 = function(sign, dot, after) {
+        peg$c39 = function(id) { return id; },
+        peg$c40 = "ne",
+        peg$c41 = { type: "literal", value: "ne", description: "\"ne\"" },
+        peg$c42 = "se",
+        peg$c43 = { type: "literal", value: "se", description: "\"se\"" },
+        peg$c44 = "sw",
+        peg$c45 = { type: "literal", value: "sw", description: "\"sw\"" },
+        peg$c46 = "nw",
+        peg$c47 = { type: "literal", value: "nw", description: "\"nw\"" },
+        peg$c48 = "n",
+        peg$c49 = { type: "literal", value: "n", description: "\"n\"" },
+        peg$c50 = "e",
+        peg$c51 = { type: "literal", value: "e", description: "\"e\"" },
+        peg$c52 = "s",
+        peg$c53 = { type: "literal", value: "s", description: "\"s\"" },
+        peg$c54 = "w",
+        peg$c55 = { type: "literal", value: "w", description: "\"w\"" },
+        peg$c56 = "c",
+        peg$c57 = { type: "literal", value: "c", description: "\"c\"" },
+        peg$c58 = "_",
+        peg$c59 = { type: "literal", value: "_", description: "\"_\"" },
+        peg$c60 = { type: "other", description: "identifier" },
+        peg$c61 = /^[a-zA-Z\u0200-\u0377_]/,
+        peg$c62 = { type: "class", value: "[a-zA-Z\\u0200-\\u0377_]", description: "[a-zA-Z\\u0200-\\u0377_]" },
+        peg$c63 = /^[a-zA-Z\u0200-\u0377_0-9]/,
+        peg$c64 = { type: "class", value: "[a-zA-Z\\u0200-\\u0377_0-9]", description: "[a-zA-Z\\u0200-\\u0377_0-9]" },
+        peg$c65 = function(fst, rest) { return fst + rest.join(""); },
+        peg$c66 = "-",
+        peg$c67 = { type: "literal", value: "-", description: "\"-\"" },
+        peg$c68 = ".",
+        peg$c69 = { type: "literal", value: ".", description: "\".\"" },
+        peg$c70 = /^[0-9]/,
+        peg$c71 = { type: "class", value: "[0-9]", description: "[0-9]" },
+        peg$c72 = function(sign, dot, after) {
               return (sign || "") + dot + after.join("");
             },
-        peg$c72 = function(sign, before, after) {
+        peg$c73 = function(sign, before, after) {
               return (sign || "") + before.join("") + (after ? after[0] : "") + (after ? after[1].join("") : "");
             },
-        peg$c73 = "\"",
-        peg$c74 = { type: "literal", value: "\"", description: "\"\\\"\"" },
-        peg$c75 = "\\\"",
-        peg$c76 = { type: "literal", value: "\\\"", description: "\"\\\\\\\"\"" },
-        peg$c77 = function() { return '"'; },
-        peg$c78 = "\\",
-        peg$c79 = { type: "literal", value: "\\", description: "\"\\\\\"" },
-        peg$c80 = /^[^"]/,
-        peg$c81 = { type: "class", value: "[^\"]", description: "[^\"]" },
-        peg$c82 = function(ch) { return "\\" + ch; },
-        peg$c83 = function(id) {
+        peg$c74 = "\"",
+        peg$c75 = { type: "literal", value: "\"", description: "\"\\\"\"" },
+        peg$c76 = "\\\"",
+        peg$c77 = { type: "literal", value: "\\\"", description: "\"\\\\\\\"\"" },
+        peg$c78 = function() { return '"'; },
+        peg$c79 = "\\",
+        peg$c80 = { type: "literal", value: "\\", description: "\"\\\\\"" },
+        peg$c81 = /^[^"]/,
+        peg$c82 = { type: "class", value: "[^\"]", description: "[^\"]" },
+        peg$c83 = function(ch) { return "\\" + ch; },
+        peg$c84 = function(id) {
               return id.join("");
             },
-        peg$c84 = "node",
-        peg$c85 = { type: "literal", value: "node", description: "\"node\"" },
-        peg$c86 = function(k) { return k.toLowerCase(); },
-        peg$c87 = "edge",
-        peg$c88 = { type: "literal", value: "edge", description: "\"edge\"" },
-        peg$c89 = "graph",
-        peg$c90 = { type: "literal", value: "graph", description: "\"graph\"" },
-        peg$c91 = "digraph",
-        peg$c92 = { type: "literal", value: "digraph", description: "\"digraph\"" },
-        peg$c93 = "subgraph",
-        peg$c94 = { type: "literal", value: "subgraph", description: "\"subgraph\"" },
-        peg$c95 = "strict",
-        peg$c96 = { type: "literal", value: "strict", description: "\"strict\"" },
-        peg$c97 = function(graph) {
+        peg$c85 = "node",
+        peg$c86 = { type: "literal", value: "node", description: "\"node\"" },
+        peg$c87 = function(k) { return k.toLowerCase(); },
+        peg$c88 = "edge",
+        peg$c89 = { type: "literal", value: "edge", description: "\"edge\"" },
+        peg$c90 = "graph",
+        peg$c91 = { type: "literal", value: "graph", description: "\"graph\"" },
+        peg$c92 = "digraph",
+        peg$c93 = { type: "literal", value: "digraph", description: "\"digraph\"" },
+        peg$c94 = "subgraph",
+        peg$c95 = { type: "literal", value: "subgraph", description: "\"subgraph\"" },
+        peg$c96 = "strict",
+        peg$c97 = { type: "literal", value: "strict", description: "\"strict\"" },
+        peg$c98 = function(graph) {
               directed = graph === "digraph";
               return graph;
             },
-        peg$c98 = { type: "other", description: "whitespace" },
-        peg$c99 = /^[ \t\r\n]/,
-        peg$c100 = { type: "class", value: "[ \\t\\r\\n]", description: "[ \\t\\r\\n]" },
-        peg$c101 = { type: "other", description: "comment" },
-        peg$c102 = "//",
-        peg$c103 = { type: "literal", value: "//", description: "\"//\"" },
-        peg$c104 = /^[^\n]/,
-        peg$c105 = { type: "class", value: "[^\\n]", description: "[^\\n]" },
-        peg$c106 = "/*",
-        peg$c107 = { type: "literal", value: "/*", description: "\"/*\"" },
-        peg$c108 = "*/",
-        peg$c109 = { type: "literal", value: "*/", description: "\"*/\"" },
-        peg$c110 = { type: "any", description: "any character" },
+        peg$c99 = { type: "other", description: "whitespace" },
+        peg$c100 = /^[ \t\r\n]/,
+        peg$c101 = { type: "class", value: "[ \\t\\r\\n]", description: "[ \\t\\r\\n]" },
+        peg$c102 = { type: "other", description: "comment" },
+        peg$c103 = "//",
+        peg$c104 = { type: "literal", value: "//", description: "\"//\"" },
+        peg$c105 = /^[^\n]/,
+        peg$c106 = { type: "class", value: "[^\\n]", description: "[^\\n]" },
+        peg$c107 = "/*",
+        peg$c108 = { type: "literal", value: "/*", description: "\"/*\"" },
+        peg$c109 = "*/",
+        peg$c110 = { type: "literal", value: "*/", description: "\"*/\"" },
+        peg$c111 = { type: "any", description: "any character" },
 
         peg$currPos          = 0,
         peg$reportedPos      = 0,
@@ -1468,7 +1472,7 @@ module.exports = (function() {
           }
           if (s3 !== peg$FAILED) {
             peg$reportedPos = s0;
-            s1 = peg$c36(s1);
+            s1 = peg$c36(s1, s3);
             s0 = s1;
           } else {
             peg$currPos = s0;
@@ -1550,7 +1554,8 @@ module.exports = (function() {
                 s5 = peg$c2;
               }
               if (s5 !== peg$FAILED) {
-                s1 = [s1, s2, s3, s4, s5];
+                peg$reportedPos = s0;
+                s1 = peg$c39(s3);
                 s0 = s1;
               } else {
                 peg$currPos = s0;
@@ -1579,84 +1584,84 @@ module.exports = (function() {
     function peg$parsecompassPt() {
       var s0;
 
-      if (input.substr(peg$currPos, 2) === peg$c39) {
-        s0 = peg$c39;
+      if (input.substr(peg$currPos, 2) === peg$c40) {
+        s0 = peg$c40;
         peg$currPos += 2;
       } else {
         s0 = peg$FAILED;
-        if (peg$silentFails === 0) { peg$fail(peg$c40); }
+        if (peg$silentFails === 0) { peg$fail(peg$c41); }
       }
       if (s0 === peg$FAILED) {
-        if (input.substr(peg$currPos, 2) === peg$c41) {
-          s0 = peg$c41;
+        if (input.substr(peg$currPos, 2) === peg$c42) {
+          s0 = peg$c42;
           peg$currPos += 2;
         } else {
           s0 = peg$FAILED;
-          if (peg$silentFails === 0) { peg$fail(peg$c42); }
+          if (peg$silentFails === 0) { peg$fail(peg$c43); }
         }
         if (s0 === peg$FAILED) {
-          if (input.substr(peg$currPos, 2) === peg$c43) {
-            s0 = peg$c43;
+          if (input.substr(peg$currPos, 2) === peg$c44) {
+            s0 = peg$c44;
             peg$currPos += 2;
           } else {
             s0 = peg$FAILED;
-            if (peg$silentFails === 0) { peg$fail(peg$c44); }
+            if (peg$silentFails === 0) { peg$fail(peg$c45); }
           }
           if (s0 === peg$FAILED) {
-            if (input.substr(peg$currPos, 2) === peg$c45) {
-              s0 = peg$c45;
+            if (input.substr(peg$currPos, 2) === peg$c46) {
+              s0 = peg$c46;
               peg$currPos += 2;
             } else {
               s0 = peg$FAILED;
-              if (peg$silentFails === 0) { peg$fail(peg$c46); }
+              if (peg$silentFails === 0) { peg$fail(peg$c47); }
             }
             if (s0 === peg$FAILED) {
               if (input.charCodeAt(peg$currPos) === 110) {
-                s0 = peg$c47;
+                s0 = peg$c48;
                 peg$currPos++;
               } else {
                 s0 = peg$FAILED;
-                if (peg$silentFails === 0) { peg$fail(peg$c48); }
+                if (peg$silentFails === 0) { peg$fail(peg$c49); }
               }
               if (s0 === peg$FAILED) {
                 if (input.charCodeAt(peg$currPos) === 101) {
-                  s0 = peg$c49;
+                  s0 = peg$c50;
                   peg$currPos++;
                 } else {
                   s0 = peg$FAILED;
-                  if (peg$silentFails === 0) { peg$fail(peg$c50); }
+                  if (peg$silentFails === 0) { peg$fail(peg$c51); }
                 }
                 if (s0 === peg$FAILED) {
                   if (input.charCodeAt(peg$currPos) === 115) {
-                    s0 = peg$c51;
+                    s0 = peg$c52;
                     peg$currPos++;
                   } else {
                     s0 = peg$FAILED;
-                    if (peg$silentFails === 0) { peg$fail(peg$c52); }
+                    if (peg$silentFails === 0) { peg$fail(peg$c53); }
                   }
                   if (s0 === peg$FAILED) {
                     if (input.charCodeAt(peg$currPos) === 119) {
-                      s0 = peg$c53;
+                      s0 = peg$c54;
                       peg$currPos++;
                     } else {
                       s0 = peg$FAILED;
-                      if (peg$silentFails === 0) { peg$fail(peg$c54); }
+                      if (peg$silentFails === 0) { peg$fail(peg$c55); }
                     }
                     if (s0 === peg$FAILED) {
                       if (input.charCodeAt(peg$currPos) === 99) {
-                        s0 = peg$c55;
+                        s0 = peg$c56;
                         peg$currPos++;
                       } else {
                         s0 = peg$FAILED;
-                        if (peg$silentFails === 0) { peg$fail(peg$c56); }
+                        if (peg$silentFails === 0) { peg$fail(peg$c57); }
                       }
                       if (s0 === peg$FAILED) {
                         if (input.charCodeAt(peg$currPos) === 95) {
-                          s0 = peg$c57;
+                          s0 = peg$c58;
                           peg$currPos++;
                         } else {
                           s0 = peg$FAILED;
-                          if (peg$silentFails === 0) { peg$fail(peg$c58); }
+                          if (peg$silentFails === 0) { peg$fail(peg$c59); }
                         }
                       }
                     }
@@ -1676,35 +1681,35 @@ module.exports = (function() {
 
       peg$silentFails++;
       s0 = peg$currPos;
-      if (peg$c60.test(input.charAt(peg$currPos))) {
+      if (peg$c61.test(input.charAt(peg$currPos))) {
         s1 = input.charAt(peg$currPos);
         peg$currPos++;
       } else {
         s1 = peg$FAILED;
-        if (peg$silentFails === 0) { peg$fail(peg$c61); }
+        if (peg$silentFails === 0) { peg$fail(peg$c62); }
       }
       if (s1 !== peg$FAILED) {
         s2 = [];
-        if (peg$c62.test(input.charAt(peg$currPos))) {
+        if (peg$c63.test(input.charAt(peg$currPos))) {
           s3 = input.charAt(peg$currPos);
           peg$currPos++;
         } else {
           s3 = peg$FAILED;
-          if (peg$silentFails === 0) { peg$fail(peg$c63); }
+          if (peg$silentFails === 0) { peg$fail(peg$c64); }
         }
         while (s3 !== peg$FAILED) {
           s2.push(s3);
-          if (peg$c62.test(input.charAt(peg$currPos))) {
+          if (peg$c63.test(input.charAt(peg$currPos))) {
             s3 = input.charAt(peg$currPos);
             peg$currPos++;
           } else {
             s3 = peg$FAILED;
-            if (peg$silentFails === 0) { peg$fail(peg$c63); }
+            if (peg$silentFails === 0) { peg$fail(peg$c64); }
           }
         }
         if (s2 !== peg$FAILED) {
           peg$reportedPos = s0;
-          s1 = peg$c64(s1, s2);
+          s1 = peg$c65(s1, s2);
           s0 = s1;
         } else {
           peg$currPos = s0;
@@ -1717,41 +1722,41 @@ module.exports = (function() {
       if (s0 === peg$FAILED) {
         s0 = peg$currPos;
         if (input.charCodeAt(peg$currPos) === 45) {
-          s1 = peg$c65;
+          s1 = peg$c66;
           peg$currPos++;
         } else {
           s1 = peg$FAILED;
-          if (peg$silentFails === 0) { peg$fail(peg$c66); }
+          if (peg$silentFails === 0) { peg$fail(peg$c67); }
         }
         if (s1 === peg$FAILED) {
           s1 = peg$c2;
         }
         if (s1 !== peg$FAILED) {
           if (input.charCodeAt(peg$currPos) === 46) {
-            s2 = peg$c67;
+            s2 = peg$c68;
             peg$currPos++;
           } else {
             s2 = peg$FAILED;
-            if (peg$silentFails === 0) { peg$fail(peg$c68); }
+            if (peg$silentFails === 0) { peg$fail(peg$c69); }
           }
           if (s2 !== peg$FAILED) {
             s3 = [];
-            if (peg$c69.test(input.charAt(peg$currPos))) {
+            if (peg$c70.test(input.charAt(peg$currPos))) {
               s4 = input.charAt(peg$currPos);
               peg$currPos++;
             } else {
               s4 = peg$FAILED;
-              if (peg$silentFails === 0) { peg$fail(peg$c70); }
+              if (peg$silentFails === 0) { peg$fail(peg$c71); }
             }
             if (s4 !== peg$FAILED) {
               while (s4 !== peg$FAILED) {
                 s3.push(s4);
-                if (peg$c69.test(input.charAt(peg$currPos))) {
+                if (peg$c70.test(input.charAt(peg$currPos))) {
                   s4 = input.charAt(peg$currPos);
                   peg$currPos++;
                 } else {
                   s4 = peg$FAILED;
-                  if (peg$silentFails === 0) { peg$fail(peg$c70); }
+                  if (peg$silentFails === 0) { peg$fail(peg$c71); }
                 }
               }
             } else {
@@ -1759,7 +1764,7 @@ module.exports = (function() {
             }
             if (s3 !== peg$FAILED) {
               peg$reportedPos = s0;
-              s1 = peg$c71(s1, s2, s3);
+              s1 = peg$c72(s1, s2, s3);
               s0 = s1;
             } else {
               peg$currPos = s0;
@@ -1776,33 +1781,33 @@ module.exports = (function() {
         if (s0 === peg$FAILED) {
           s0 = peg$currPos;
           if (input.charCodeAt(peg$currPos) === 45) {
-            s1 = peg$c65;
+            s1 = peg$c66;
             peg$currPos++;
           } else {
             s1 = peg$FAILED;
-            if (peg$silentFails === 0) { peg$fail(peg$c66); }
+            if (peg$silentFails === 0) { peg$fail(peg$c67); }
           }
           if (s1 === peg$FAILED) {
             s1 = peg$c2;
           }
           if (s1 !== peg$FAILED) {
             s2 = [];
-            if (peg$c69.test(input.charAt(peg$currPos))) {
+            if (peg$c70.test(input.charAt(peg$currPos))) {
               s3 = input.charAt(peg$currPos);
               peg$currPos++;
             } else {
               s3 = peg$FAILED;
-              if (peg$silentFails === 0) { peg$fail(peg$c70); }
+              if (peg$silentFails === 0) { peg$fail(peg$c71); }
             }
             if (s3 !== peg$FAILED) {
               while (s3 !== peg$FAILED) {
                 s2.push(s3);
-                if (peg$c69.test(input.charAt(peg$currPos))) {
+                if (peg$c70.test(input.charAt(peg$currPos))) {
                   s3 = input.charAt(peg$currPos);
                   peg$currPos++;
                 } else {
                   s3 = peg$FAILED;
-                  if (peg$silentFails === 0) { peg$fail(peg$c70); }
+                  if (peg$silentFails === 0) { peg$fail(peg$c71); }
                 }
               }
             } else {
@@ -1811,29 +1816,29 @@ module.exports = (function() {
             if (s2 !== peg$FAILED) {
               s3 = peg$currPos;
               if (input.charCodeAt(peg$currPos) === 46) {
-                s4 = peg$c67;
+                s4 = peg$c68;
                 peg$currPos++;
               } else {
                 s4 = peg$FAILED;
-                if (peg$silentFails === 0) { peg$fail(peg$c68); }
+                if (peg$silentFails === 0) { peg$fail(peg$c69); }
               }
               if (s4 !== peg$FAILED) {
                 s5 = [];
-                if (peg$c69.test(input.charAt(peg$currPos))) {
+                if (peg$c70.test(input.charAt(peg$currPos))) {
                   s6 = input.charAt(peg$currPos);
                   peg$currPos++;
                 } else {
                   s6 = peg$FAILED;
-                  if (peg$silentFails === 0) { peg$fail(peg$c70); }
+                  if (peg$silentFails === 0) { peg$fail(peg$c71); }
                 }
                 while (s6 !== peg$FAILED) {
                   s5.push(s6);
-                  if (peg$c69.test(input.charAt(peg$currPos))) {
+                  if (peg$c70.test(input.charAt(peg$currPos))) {
                     s6 = input.charAt(peg$currPos);
                     peg$currPos++;
                   } else {
                     s6 = peg$FAILED;
-                    if (peg$silentFails === 0) { peg$fail(peg$c70); }
+                    if (peg$silentFails === 0) { peg$fail(peg$c71); }
                   }
                 }
                 if (s5 !== peg$FAILED) {
@@ -1852,7 +1857,7 @@ module.exports = (function() {
               }
               if (s3 !== peg$FAILED) {
                 peg$reportedPos = s0;
-                s1 = peg$c72(s1, s2, s3);
+                s1 = peg$c73(s1, s2, s3);
                 s0 = s1;
               } else {
                 peg$currPos = s0;
@@ -1869,47 +1874,47 @@ module.exports = (function() {
           if (s0 === peg$FAILED) {
             s0 = peg$currPos;
             if (input.charCodeAt(peg$currPos) === 34) {
-              s1 = peg$c73;
+              s1 = peg$c74;
               peg$currPos++;
             } else {
               s1 = peg$FAILED;
-              if (peg$silentFails === 0) { peg$fail(peg$c74); }
+              if (peg$silentFails === 0) { peg$fail(peg$c75); }
             }
             if (s1 !== peg$FAILED) {
               s2 = [];
               s3 = peg$currPos;
-              if (input.substr(peg$currPos, 2) === peg$c75) {
-                s4 = peg$c75;
+              if (input.substr(peg$currPos, 2) === peg$c76) {
+                s4 = peg$c76;
                 peg$currPos += 2;
               } else {
                 s4 = peg$FAILED;
-                if (peg$silentFails === 0) { peg$fail(peg$c76); }
+                if (peg$silentFails === 0) { peg$fail(peg$c77); }
               }
               if (s4 !== peg$FAILED) {
                 peg$reportedPos = s3;
-                s4 = peg$c77();
+                s4 = peg$c78();
               }
               s3 = s4;
               if (s3 === peg$FAILED) {
                 s3 = peg$currPos;
                 if (input.charCodeAt(peg$currPos) === 92) {
-                  s4 = peg$c78;
+                  s4 = peg$c79;
                   peg$currPos++;
                 } else {
                   s4 = peg$FAILED;
-                  if (peg$silentFails === 0) { peg$fail(peg$c79); }
+                  if (peg$silentFails === 0) { peg$fail(peg$c80); }
                 }
                 if (s4 !== peg$FAILED) {
-                  if (peg$c80.test(input.charAt(peg$currPos))) {
+                  if (peg$c81.test(input.charAt(peg$currPos))) {
                     s5 = input.charAt(peg$currPos);
                     peg$currPos++;
                   } else {
                     s5 = peg$FAILED;
-                    if (peg$silentFails === 0) { peg$fail(peg$c81); }
+                    if (peg$silentFails === 0) { peg$fail(peg$c82); }
                   }
                   if (s5 !== peg$FAILED) {
                     peg$reportedPos = s3;
-                    s4 = peg$c82(s5);
+                    s4 = peg$c83(s5);
                     s3 = s4;
                   } else {
                     peg$currPos = s3;
@@ -1920,50 +1925,50 @@ module.exports = (function() {
                   s3 = peg$c1;
                 }
                 if (s3 === peg$FAILED) {
-                  if (peg$c80.test(input.charAt(peg$currPos))) {
+                  if (peg$c81.test(input.charAt(peg$currPos))) {
                     s3 = input.charAt(peg$currPos);
                     peg$currPos++;
                   } else {
                     s3 = peg$FAILED;
-                    if (peg$silentFails === 0) { peg$fail(peg$c81); }
+                    if (peg$silentFails === 0) { peg$fail(peg$c82); }
                   }
                 }
               }
               while (s3 !== peg$FAILED) {
                 s2.push(s3);
                 s3 = peg$currPos;
-                if (input.substr(peg$currPos, 2) === peg$c75) {
-                  s4 = peg$c75;
+                if (input.substr(peg$currPos, 2) === peg$c76) {
+                  s4 = peg$c76;
                   peg$currPos += 2;
                 } else {
                   s4 = peg$FAILED;
-                  if (peg$silentFails === 0) { peg$fail(peg$c76); }
+                  if (peg$silentFails === 0) { peg$fail(peg$c77); }
                 }
                 if (s4 !== peg$FAILED) {
                   peg$reportedPos = s3;
-                  s4 = peg$c77();
+                  s4 = peg$c78();
                 }
                 s3 = s4;
                 if (s3 === peg$FAILED) {
                   s3 = peg$currPos;
                   if (input.charCodeAt(peg$currPos) === 92) {
-                    s4 = peg$c78;
+                    s4 = peg$c79;
                     peg$currPos++;
                   } else {
                     s4 = peg$FAILED;
-                    if (peg$silentFails === 0) { peg$fail(peg$c79); }
+                    if (peg$silentFails === 0) { peg$fail(peg$c80); }
                   }
                   if (s4 !== peg$FAILED) {
-                    if (peg$c80.test(input.charAt(peg$currPos))) {
+                    if (peg$c81.test(input.charAt(peg$currPos))) {
                       s5 = input.charAt(peg$currPos);
                       peg$currPos++;
                     } else {
                       s5 = peg$FAILED;
-                      if (peg$silentFails === 0) { peg$fail(peg$c81); }
+                      if (peg$silentFails === 0) { peg$fail(peg$c82); }
                     }
                     if (s5 !== peg$FAILED) {
                       peg$reportedPos = s3;
-                      s4 = peg$c82(s5);
+                      s4 = peg$c83(s5);
                       s3 = s4;
                     } else {
                       peg$currPos = s3;
@@ -1974,27 +1979,27 @@ module.exports = (function() {
                     s3 = peg$c1;
                   }
                   if (s3 === peg$FAILED) {
-                    if (peg$c80.test(input.charAt(peg$currPos))) {
+                    if (peg$c81.test(input.charAt(peg$currPos))) {
                       s3 = input.charAt(peg$currPos);
                       peg$currPos++;
                     } else {
                       s3 = peg$FAILED;
-                      if (peg$silentFails === 0) { peg$fail(peg$c81); }
+                      if (peg$silentFails === 0) { peg$fail(peg$c82); }
                     }
                   }
                 }
               }
               if (s2 !== peg$FAILED) {
                 if (input.charCodeAt(peg$currPos) === 34) {
-                  s3 = peg$c73;
+                  s3 = peg$c74;
                   peg$currPos++;
                 } else {
                   s3 = peg$FAILED;
-                  if (peg$silentFails === 0) { peg$fail(peg$c74); }
+                  if (peg$silentFails === 0) { peg$fail(peg$c75); }
                 }
                 if (s3 !== peg$FAILED) {
                   peg$reportedPos = s0;
-                  s1 = peg$c83(s2);
+                  s1 = peg$c84(s2);
                   s0 = s1;
                 } else {
                   peg$currPos = s0;
@@ -2014,7 +2019,7 @@ module.exports = (function() {
       peg$silentFails--;
       if (s0 === peg$FAILED) {
         s1 = peg$FAILED;
-        if (peg$silentFails === 0) { peg$fail(peg$c59); }
+        if (peg$silentFails === 0) { peg$fail(peg$c60); }
       }
 
       return s0;
@@ -2024,16 +2029,16 @@ module.exports = (function() {
       var s0, s1;
 
       s0 = peg$currPos;
-      if (input.substr(peg$currPos, 4).toLowerCase() === peg$c84) {
+      if (input.substr(peg$currPos, 4).toLowerCase() === peg$c85) {
         s1 = input.substr(peg$currPos, 4);
         peg$currPos += 4;
       } else {
         s1 = peg$FAILED;
-        if (peg$silentFails === 0) { peg$fail(peg$c85); }
+        if (peg$silentFails === 0) { peg$fail(peg$c86); }
       }
       if (s1 !== peg$FAILED) {
         peg$reportedPos = s0;
-        s1 = peg$c86(s1);
+        s1 = peg$c87(s1);
       }
       s0 = s1;
 
@@ -2044,16 +2049,16 @@ module.exports = (function() {
       var s0, s1;
 
       s0 = peg$currPos;
-      if (input.substr(peg$currPos, 4).toLowerCase() === peg$c87) {
+      if (input.substr(peg$currPos, 4).toLowerCase() === peg$c88) {
         s1 = input.substr(peg$currPos, 4);
         peg$currPos += 4;
       } else {
         s1 = peg$FAILED;
-        if (peg$silentFails === 0) { peg$fail(peg$c88); }
+        if (peg$silentFails === 0) { peg$fail(peg$c89); }
       }
       if (s1 !== peg$FAILED) {
         peg$reportedPos = s0;
-        s1 = peg$c86(s1);
+        s1 = peg$c87(s1);
       }
       s0 = s1;
 
@@ -2064,16 +2069,16 @@ module.exports = (function() {
       var s0, s1;
 
       s0 = peg$currPos;
-      if (input.substr(peg$currPos, 5).toLowerCase() === peg$c89) {
+      if (input.substr(peg$currPos, 5).toLowerCase() === peg$c90) {
         s1 = input.substr(peg$currPos, 5);
         peg$currPos += 5;
       } else {
         s1 = peg$FAILED;
-        if (peg$silentFails === 0) { peg$fail(peg$c90); }
+        if (peg$silentFails === 0) { peg$fail(peg$c91); }
       }
       if (s1 !== peg$FAILED) {
         peg$reportedPos = s0;
-        s1 = peg$c86(s1);
+        s1 = peg$c87(s1);
       }
       s0 = s1;
 
@@ -2084,16 +2089,16 @@ module.exports = (function() {
       var s0, s1;
 
       s0 = peg$currPos;
-      if (input.substr(peg$currPos, 7).toLowerCase() === peg$c91) {
+      if (input.substr(peg$currPos, 7).toLowerCase() === peg$c92) {
         s1 = input.substr(peg$currPos, 7);
         peg$currPos += 7;
       } else {
         s1 = peg$FAILED;
-        if (peg$silentFails === 0) { peg$fail(peg$c92); }
+        if (peg$silentFails === 0) { peg$fail(peg$c93); }
       }
       if (s1 !== peg$FAILED) {
         peg$reportedPos = s0;
-        s1 = peg$c86(s1);
+        s1 = peg$c87(s1);
       }
       s0 = s1;
 
@@ -2104,16 +2109,16 @@ module.exports = (function() {
       var s0, s1;
 
       s0 = peg$currPos;
-      if (input.substr(peg$currPos, 8).toLowerCase() === peg$c93) {
+      if (input.substr(peg$currPos, 8).toLowerCase() === peg$c94) {
         s1 = input.substr(peg$currPos, 8);
         peg$currPos += 8;
       } else {
         s1 = peg$FAILED;
-        if (peg$silentFails === 0) { peg$fail(peg$c94); }
+        if (peg$silentFails === 0) { peg$fail(peg$c95); }
       }
       if (s1 !== peg$FAILED) {
         peg$reportedPos = s0;
-        s1 = peg$c86(s1);
+        s1 = peg$c87(s1);
       }
       s0 = s1;
 
@@ -2124,16 +2129,16 @@ module.exports = (function() {
       var s0, s1;
 
       s0 = peg$currPos;
-      if (input.substr(peg$currPos, 6).toLowerCase() === peg$c95) {
+      if (input.substr(peg$currPos, 6).toLowerCase() === peg$c96) {
         s1 = input.substr(peg$currPos, 6);
         peg$currPos += 6;
       } else {
         s1 = peg$FAILED;
-        if (peg$silentFails === 0) { peg$fail(peg$c96); }
+        if (peg$silentFails === 0) { peg$fail(peg$c97); }
       }
       if (s1 !== peg$FAILED) {
         peg$reportedPos = s0;
-        s1 = peg$c86(s1);
+        s1 = peg$c87(s1);
       }
       s0 = s1;
 
@@ -2149,7 +2154,7 @@ module.exports = (function() {
         s1 = peg$parsedigraph();
         if (s1 !== peg$FAILED) {
           peg$reportedPos = s0;
-          s1 = peg$c97(s1);
+          s1 = peg$c98(s1);
         }
         s0 = s1;
       }
@@ -2162,22 +2167,22 @@ module.exports = (function() {
 
       peg$silentFails++;
       s0 = [];
-      if (peg$c99.test(input.charAt(peg$currPos))) {
+      if (peg$c100.test(input.charAt(peg$currPos))) {
         s1 = input.charAt(peg$currPos);
         peg$currPos++;
       } else {
         s1 = peg$FAILED;
-        if (peg$silentFails === 0) { peg$fail(peg$c100); }
+        if (peg$silentFails === 0) { peg$fail(peg$c101); }
       }
       if (s1 !== peg$FAILED) {
         while (s1 !== peg$FAILED) {
           s0.push(s1);
-          if (peg$c99.test(input.charAt(peg$currPos))) {
+          if (peg$c100.test(input.charAt(peg$currPos))) {
             s1 = input.charAt(peg$currPos);
             peg$currPos++;
           } else {
             s1 = peg$FAILED;
-            if (peg$silentFails === 0) { peg$fail(peg$c100); }
+            if (peg$silentFails === 0) { peg$fail(peg$c101); }
           }
         }
       } else {
@@ -2186,7 +2191,7 @@ module.exports = (function() {
       peg$silentFails--;
       if (s0 === peg$FAILED) {
         s1 = peg$FAILED;
-        if (peg$silentFails === 0) { peg$fail(peg$c98); }
+        if (peg$silentFails === 0) { peg$fail(peg$c99); }
       }
 
       return s0;
@@ -2197,30 +2202,30 @@ module.exports = (function() {
 
       peg$silentFails++;
       s0 = peg$currPos;
-      if (input.substr(peg$currPos, 2) === peg$c102) {
-        s1 = peg$c102;
+      if (input.substr(peg$currPos, 2) === peg$c103) {
+        s1 = peg$c103;
         peg$currPos += 2;
       } else {
         s1 = peg$FAILED;
-        if (peg$silentFails === 0) { peg$fail(peg$c103); }
+        if (peg$silentFails === 0) { peg$fail(peg$c104); }
       }
       if (s1 !== peg$FAILED) {
         s2 = [];
-        if (peg$c104.test(input.charAt(peg$currPos))) {
+        if (peg$c105.test(input.charAt(peg$currPos))) {
           s3 = input.charAt(peg$currPos);
           peg$currPos++;
         } else {
           s3 = peg$FAILED;
-          if (peg$silentFails === 0) { peg$fail(peg$c105); }
+          if (peg$silentFails === 0) { peg$fail(peg$c106); }
         }
         while (s3 !== peg$FAILED) {
           s2.push(s3);
-          if (peg$c104.test(input.charAt(peg$currPos))) {
+          if (peg$c105.test(input.charAt(peg$currPos))) {
             s3 = input.charAt(peg$currPos);
             peg$currPos++;
           } else {
             s3 = peg$FAILED;
-            if (peg$silentFails === 0) { peg$fail(peg$c105); }
+            if (peg$silentFails === 0) { peg$fail(peg$c106); }
           }
         }
         if (s2 !== peg$FAILED) {
@@ -2236,24 +2241,24 @@ module.exports = (function() {
       }
       if (s0 === peg$FAILED) {
         s0 = peg$currPos;
-        if (input.substr(peg$currPos, 2) === peg$c106) {
-          s1 = peg$c106;
+        if (input.substr(peg$currPos, 2) === peg$c107) {
+          s1 = peg$c107;
           peg$currPos += 2;
         } else {
           s1 = peg$FAILED;
-          if (peg$silentFails === 0) { peg$fail(peg$c107); }
+          if (peg$silentFails === 0) { peg$fail(peg$c108); }
         }
         if (s1 !== peg$FAILED) {
           s2 = [];
           s3 = peg$currPos;
           s4 = peg$currPos;
           peg$silentFails++;
-          if (input.substr(peg$currPos, 2) === peg$c108) {
-            s5 = peg$c108;
+          if (input.substr(peg$currPos, 2) === peg$c109) {
+            s5 = peg$c109;
             peg$currPos += 2;
           } else {
             s5 = peg$FAILED;
-            if (peg$silentFails === 0) { peg$fail(peg$c109); }
+            if (peg$silentFails === 0) { peg$fail(peg$c110); }
           }
           peg$silentFails--;
           if (s5 === peg$FAILED) {
@@ -2268,7 +2273,7 @@ module.exports = (function() {
               peg$currPos++;
             } else {
               s5 = peg$FAILED;
-              if (peg$silentFails === 0) { peg$fail(peg$c110); }
+              if (peg$silentFails === 0) { peg$fail(peg$c111); }
             }
             if (s5 !== peg$FAILED) {
               s4 = [s4, s5];
@@ -2286,12 +2291,12 @@ module.exports = (function() {
             s3 = peg$currPos;
             s4 = peg$currPos;
             peg$silentFails++;
-            if (input.substr(peg$currPos, 2) === peg$c108) {
-              s5 = peg$c108;
+            if (input.substr(peg$currPos, 2) === peg$c109) {
+              s5 = peg$c109;
               peg$currPos += 2;
             } else {
               s5 = peg$FAILED;
-              if (peg$silentFails === 0) { peg$fail(peg$c109); }
+              if (peg$silentFails === 0) { peg$fail(peg$c110); }
             }
             peg$silentFails--;
             if (s5 === peg$FAILED) {
@@ -2306,7 +2311,7 @@ module.exports = (function() {
                 peg$currPos++;
               } else {
                 s5 = peg$FAILED;
-                if (peg$silentFails === 0) { peg$fail(peg$c110); }
+                if (peg$silentFails === 0) { peg$fail(peg$c111); }
               }
               if (s5 !== peg$FAILED) {
                 s4 = [s4, s5];
@@ -2321,12 +2326,12 @@ module.exports = (function() {
             }
           }
           if (s2 !== peg$FAILED) {
-            if (input.substr(peg$currPos, 2) === peg$c108) {
-              s3 = peg$c108;
+            if (input.substr(peg$currPos, 2) === peg$c109) {
+              s3 = peg$c109;
               peg$currPos += 2;
             } else {
               s3 = peg$FAILED;
-              if (peg$silentFails === 0) { peg$fail(peg$c109); }
+              if (peg$silentFails === 0) { peg$fail(peg$c110); }
             }
             if (s3 !== peg$FAILED) {
               s1 = [s1, s2, s3];
@@ -2347,7 +2352,7 @@ module.exports = (function() {
       peg$silentFails--;
       if (s0 === peg$FAILED) {
         s1 = peg$FAILED;
-        if (peg$silentFails === 0) { peg$fail(peg$c101); }
+        if (peg$silentFails === 0) { peg$fail(peg$c102); }
       }
 
       return s0;
diff --git a/src/dot-grammar.pegjs b/src/dot-grammar.pegjs
index cbd311e..2bb7a95 100644
--- a/src/dot-grammar.pegjs
+++ b/src/dot-grammar.pegjs
@@ -43,10 +43,10 @@ inlineAttrStmt
       var attrs = {};
       attrs[k] = v;
       return { type: "inlineAttr", attrs: attrs };
-    } 
+    }
 
 nodeStmt
-  = id:nodeId _* attrs:attrList? { return {type: "node", id: id, attrs: attrs || {}}; }
+  = nodeId:nodeId _* attrs:attrList? { return {type: "node", id: nodeId.id, port: nodeId.port, attrs: attrs || {}}; }
 
 edgeStmt
   = lhs:(nodeIdOrSubgraph) _* rhs:edgeRHS _* attrs:attrList? {
@@ -104,13 +104,16 @@ idDef
 
 nodeIdOrSubgraph
   = subgraphStmt
-  / id:nodeId { return { type: "node", id: id, attrs: {} }; }
+  / nodeId:nodeId {
+    var attrs = {}
+    return { type: "node", id: nodeId.id, port: nodeId.port, attrs: attrs };
+  }
 
 nodeId
-  = id:id _* port? { return id; }
+  = id:id _* port:port? { return { id: id, port: port }; }
 
 port
-  = ':' _* id _* (':' _* compassPt)?
+  = ':' _* id:id  _* (':' _* compassPt)? { return id; }
 
 compassPt
   = "ne" / "se" / "sw" / "nw" / "n" / "e" / "s" / "w" / "c" / "_"
diff --git a/test/read-one-test.js b/test/read-one-test.js
index f5dee4d..92b2fe4 100644
--- a/test/read-one-test.js
+++ b/test/read-one-test.js
@@ -339,6 +339,29 @@ describe("read", function() {
     });
   });
 
+  describe("ports", function() {
+    it("allows ports on edges", function() {
+      var g = read("digraph { a:foo -> b:bar -> c:baz }");
+      expect(g.edge("a", "b")).to.eql({ $out: "foo", $in: "bar" });
+      expect(g.edge("b", "c")).to.eql({ $out: "bar", $in: "baz" });
+    });
+
+    it("allow recieving port", function() {
+      var g = read("digraph { a -> b:bar }");
+      expect(g.edge("a", "b")).to.eql({ $in: "bar" });
+    });
+
+    it("allow sending port", function() {
+      var g = read("digraph { a:foo -> b }");
+      expect(g.edge("a", "b")).to.eql({ $out: "foo" });
+    });
+
+    it("allow multiple outs", function() {
+      var g = read("digraph { a:foo -> b; a:bar -> b; a:baz -> b }");
+      expect(g.edgeCount()).to.equal(3);
+    });
+  });
+
   describe("failure cases", function() {
     it("fails if the graph block is not closed", function() {
       expect(function() { read("digraph {"); }).to.throw();