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README.md

-# 2019-networking
+# Overview 2019-networking
 
-Public repository for reproducibility of our IFIP Networking 2019 paper
\ No newline at end of file
+This repository contains a simple framework for routing for reconfigurable demand-aware networks.
+The code is written in **Python3.6** and requires some few packages (see next section)
+
+The code has been the basis for computational evaluations within the following publication:
+**[1]** Thomas Fenz, Klaus-Tycho Foerster, Stefan Schmid, Anaïs Villedieu: **"Efficient Non-Segregated Routing for Reconfigurable Demand-Aware Networks"**. IFIP Networking 2019 Conference.
+
+# Dependencies and Requirements
+
+Python 3.6. Required python libraries: gurobipy, networkx, munkres, matplotlib. 
+**Note**: Our source is tested only on Linux (Ubuntu 18.04.1 LTS) and macOs (Mojave 10.14.3).  
+
+# Structure
+
+* The folder **[algorithms/heuristics](algorithms/heuristics/)** contains all implemented heuristic algorithms.
+* The folder **[algorithms/ilps](algorithms/ilps/)** contains all different versions of the implemented ilp algorithm.
+* The folder **[data_sets](data_sets/)** contains two sets of input data to test the algorithms (static topology, optical topology, demands).
+
+# Code Structure
+
+The code is structured as follows:
+
+ * **run_simple_tests.py** is the main entry point of the program. It fetches the input data from the data sets and executes all implemented algorithm.
+ * **data_sets/simple_data_set1.py** contains simple input data (static topology, optical topology, demands)
+ * **data_sets/simple_data_set2.py** contains simple input data (static topology, optical topology, demands)
+ * **algorithms/heuristics/demand_first_directed.py** contains the implementation of the Demand First (directed) algorithm
+ * **algorithms/heuristics/demand_first_undirected.py** contains the implementation of the Demand First (undirected) algorithm
+ * **algorithms/heuristics/gain_demand_directed.py** contains the implementation of the Gain Demand (directed) algorithm
+ * **algorithms/heuristics/gain_demand_undirected.py** contains the implementation of the Gain Demand (undirected) algorithm
+ * **algorithms/heuristics/gain_update_directed.py** contains the implementation of the Gain Update (directed) algorithm
+ * **algorithms/heuristics/gain_update_undirected.py** contains the implementation of the Gain Update (undirected) algorithm
+ * **algorithms/heuristics/greedy_links_directed.py** contains the implementation of the Greedy Links (directed) algorithm
+ * **algorithms/heuristics/greedy_links_undirected.py** contains the implementation of the Greedy Links (undirected) algorithm
+ * **algorithms/heuristics/heuristics_helper_directed.py** contains shared methods used by various heuristic algorithms
+ * **algorithms/heuristics/heuristics_helper_undirected.py** contains shared methods used by various heuristic algorithms
+ * **algorithms/heuristics/segregated_directed.py** contains the implementation of the Segregated (directed) algorithm
+ * **algorithms/heuristics/segregated_undirected.py** contains the implementation of the Segregated (undirected) algorithm
+ * **algorithms/ilps/ilp_directed.py** contains the implementation of the Ilp (directed) algorithm
+ * **algorithms/ilps/ilp_directed_quadratic_constraints.py** contains the implementation of the Ilp (directed) algorithm
+ * **algorithms/ilps/ilp_helper.py** contains shared methods used by various ilp algorithms
+ * **algorithms/ilps/ilp_undirected.py** contains the implementation Ilp (undirected) algorithm
+ * **algorithms/ilps/ilp_undirected_quadratic_constraints.py** contains the implementation of the Ilp (undirected) algorithm

algorithms/heuristics/demand_first_directed.py

+import networkx as nx
+import heuristics_helper_directed as helper
+
+
+def __demand_first(G, nx_static, D, optical_topology, nN, nR):
+    demand_values = []
+    demand_pair = []
+    for i, j in D:
+        demand_pair += [(i, j)]
+        demand_values += [D[(i, j)]]
+    for k in range(len(D)):
+        max_demand = max(demand_values)
+        max_index = demand_values.index(max_demand)
+        (start, end) = demand_pair[max_index]
+        if nx.shortest_path_length(nx_static, start, end, "weight") > nx.shortest_path_length(G, start, end, "weight"):
+            helper.update_graph(G, nx_static, nx.shortest_path(G, start, end, "weight"), True, optical_topology, nN, nR)
+        del demand_values[max_index]
+        del demand_pair[max_index]
+    return (nx_static)
+
+
+def solve(s, o, D):
+    ex = None
+    nx_full_topology = nx.MultiDiGraph()  # represents all currently possible edges
+    nx_static_topology = nx.MultiDiGraph()  # represents static edges and matchings made
+
+    all_arcs_ij = set([(i, j) for _, i, j in o])
+    all_arcs_ij.update(s)
+    nN = int(max(max(i, j) for i, j in all_arcs_ij) + 1)
+    nR = int(max(R for R, _, _ in o) + 1)
+    optical_topology = o
+
+    for i, j in s:
+        nx_static_topology.add_edge(i, j, weight=s[(i, j)])
+        nx_full_topology.add_edge(i, j, key=0, weight=s[(i, j)])
+    for r, i, j in o:
+        nx_full_topology.add_edge(i, j, key=r + 1, weight=o[(r, i, j)])
+    try:
+        solution = helper.get_objective(
+            __demand_first(nx_full_topology, nx_static_topology, D, optical_topology, nN, nR), D)
+    except ex as Exception:
+        return False, str(ex), ""
+    return True, "", solution

algorithms/heuristics/demand_first_undirected.py

+import copy
+import heuristics_helper_undirected as helper
+
+
+# not optimal if triangular inequality in optical links not respected
+def __demand_first(stopology, otopology, demand):
+    """
+    find the biggest demand
+    make the best matching for it
+    delete it
+    repeat until no more demands
+    """
+    s_topology = copy.deepcopy(stopology)
+    o_topology = copy.deepcopy(otopology)
+    newdemand = copy.deepcopy(demand)
+    max_demand = 0
+    max_index = 0
+    for k in range(len(demand)):
+        maxstart = 0
+        maxend = 0
+        for i, j in newdemand.keys():
+            if newdemand[(i, j)] > max_demand:
+                max_demand = newdemand[(i, j)]
+                maxstart = i
+                maxend = j
+        [path, distance] = helper.shortest_path(s_topology, o_topology, maxstart, maxend, nN, nR)
+        (s_topology, o_topology) = helper.update_graph(s_topology, o_topology, path, True, nN, nR)
+        del newdemand[(maxstart, maxend)]
+        max_demand = 0
+    return (s_topology)
+
+
+def solve(s, o, D):
+    ex = None
+    global nN  # todo this is ugly, but i don't have time to refactor the whole code
+    global nR
+    global optical_topology
+
+    all_arcs_ij = set([(i, j) for _, i, j in o])
+    all_arcs_ij.update(s)
+    nN = int(max(max(i, j) for i, j in all_arcs_ij) + 1)
+    nR = int(max(R for R, _, _ in o) + 1)
+    optical_topology = o
+
+    try:
+        solution = helper.get_objective(__demand_first(s, optical_topology, D), D, nN)
+    except ex as Exception:
+        return False, str(ex), ""
+    return True, "", solution

algorithms/heuristics/gain_demand_directed.py

+import networkx as nx
+import heuristics_helper_directed as helper
+
+
+def __gain_demand(G, nx_static, D, optical_topology, nN, nR):
+    demand_list = []
+    obj_function_list = []
+    temp_static = nx_static.copy()
+    temp_G = G.copy()
+    for i, j in D:
+        demand_list += [[i, j]]
+        if nx.shortest_path_length(temp_static, i, j, "weight") > nx.shortest_path_length(temp_G, i, j, "weight"):
+            temp_static = helper.update_graph(temp_G, temp_static, nx.shortest_path(G, i, j, "weight"), False,
+                                              optical_topology, nN, nR)
+            obj_function_list += [helper.get_objective(temp_static, D)]
+        else:
+            obj_function_list += [helper.get_objective(temp_static, D)]
+    for k in range(len(D)):
+        min_value = min(obj_function_list)
+        min_index = obj_function_list.index(min_value)
+        [start, end] = demand_list[min_index]
+        if nx.shortest_path_length(nx_static, start, end, "weight") > nx.shortest_path_length(G, start, end, "weight"):
+            helper.update_graph(G, nx_static, nx.shortest_path(G, start, end, "weight"), True, optical_topology, nN, nR)
+        del obj_function_list[min_index]
+        del demand_list[min_index]
+    return (nx_static)
+
+
+def solve(s, o, D):
+    ex = None
+    nx_full_topology = nx.MultiDiGraph()  # represents all currently possible edges
+    nx_static_topology = nx.MultiDiGraph()  # represents static edges and matching made
+
+    all_arcs_ij = set([(i, j) for _, i, j in o])
+    all_arcs_ij.update(s)
+    nN = int(max(max(i, j) for i, j in all_arcs_ij) + 1)
+    nR = int(max(R for R, _, _ in o) + 1)
+    optical_topology = o
+    for i, j in s:
+        nx_static_topology.add_edge(i, j, weight=s[(i, j)])
+        nx_full_topology.add_edge(i, j, key=0, weight=s[(i, j)])
+    for r, i, j in o:
+        nx_full_topology.add_edge(i, j, key=r + 1, weight=o[(r, i, j)])
+    try:
+        solution = helper.get_objective(
+            __gain_demand(nx_full_topology, nx_static_topology, D, optical_topology, nN, nR)
+            , D)
+
+    except ex as Exception:
+        return False, str(ex), ""
+
+    return True, "", solution

algorithms/heuristics/gain_demand_undirected.py

+import copy
+import heuristics_helper_undirected as helper
+
+
+# not optimal if triangular inequality in optical links not respected
+def __gain_demand(stopology, otopology, demand):
+    """
+    find the best graph for each demand
+    find the value of the objective function in each of these graphs
+    match the demand that got the smallest objective function
+    delete it
+    repeat until no more demands
+    """
+    s_topology = copy.deepcopy(stopology)
+    o_topology = copy.deepcopy(otopology)
+    staticpathlength = []
+    for i, j in demand:
+        (s_topology, o_topology) = helper.update_graph(s_topology, o_topology,
+                                                       helper.shortest_path(s_topology, o_topology, i, j, nN, nR)[0],
+                                                       False, nN, nR)
+        gain = helper.get_objective(s_topology, demand, nN)
+        staticpathlength += [[i, j, gain]]
+        s_topology = copy.deepcopy(stopology)
+        o_topology = copy.deepcopy(otopology)
+    min = staticpathlength[0][2]
+    for i in range(len(demand)):
+        min = staticpathlength[0][2]
+        index = 0
+        start = staticpathlength[0][0]
+        end = staticpathlength[0][1]
+        for k in range(len(staticpathlength)):
+            if staticpathlength[k][2] < min:
+                index = k
+                min = staticpathlength[k][2]
+                start = staticpathlength[k][0]
+                end = staticpathlength[k][1]
+        [path, distance] = helper.shortest_path(s_topology, o_topology, start, end, nN, nR)
+        topology = helper.update_graph(s_topology, o_topology, path, True, nN, nR)
+        del staticpathlength[index]
+    return (s_topology)
+
+
+def solve(s, o, D):
+    ex = None
+    global nN
+    global nR
+    global optical_topology
+
+    all_arcs_ij = set([(i, j) for _, i, j in o])
+    all_arcs_ij.update(s)
+    nN = int(max(max(i, j) for i, j in all_arcs_ij) + 1)
+    nR = int(max(R for R, _, _ in o) + 1)
+    optical_topology = o
+
+    try:
+        solution = helper.get_objective(__gain_demand(s, optical_topology, D), D, nN)
+    except ex as Exception:
+        return False, str(ex), ""
+
+    return True, "", solution

algorithms/heuristics/gain_update_directed.py

+import networkx as nx
+import heuristics_helper_directed as helper
+
+
+def __gain_update(G, nx_static, D, optical_topology, nN, nR):
+    obj_function_list = []
+    demands = []
+    temp_static = nx_static.copy()
+    temp_G = G.copy()
+    current_obj_fct_value = -1
+    for (i, j) in D:
+        demands += [(i, j)]
+    for k in range(len(D)):
+        for i, j in demands:
+            if nx.shortest_path_length(temp_static, i, j, "weight") > nx.shortest_path_length(temp_G, i, j, "weight"):
+                temp_static = helper.update_graph(temp_G, temp_static, nx.shortest_path(G, i, j, "weight"), False,
+                                                  optical_topology, nN, nR)
+                obj_function_list += [helper.get_objective(temp_static, D)]
+            else:
+                obj_function_list += [helper.get_objective(temp_static, D)]
+            temp_static = nx_static.copy()
+            temp_G = G.copy()
+        min_distance = min(obj_function_list)
+        if min_distance == current_obj_fct_value:
+            return (nx_static)
+        else:
+            current_obj_fct_value = min_distance
+        min_index = obj_function_list.index(min_distance)
+        (start, end) = demands[min_index]
+        if nx.shortest_path_length(nx_static, start, end, "weight") > nx.shortest_path_length(G, start, end, "weight"):
+            helper.update_graph(G, nx_static, nx.shortest_path(G, start, end, "weight"), True, optical_topology, nN, nR)
+        obj_function_list = []
+        demands.remove((start, end))
+    return (nx_static)
+
+
+def solve(s, o, D):
+    ex = None
+    nx_full_topology = nx.MultiDiGraph()  # represents all currently possible edges
+    nx_static_topology = nx.MultiDiGraph()  # represents static edges and matching made
+
+    all_arcs_ij = set([(i, j) for _, i, j in o])
+    all_arcs_ij.update(s)
+    nN = int(max(max(i, j) for i, j in all_arcs_ij) + 1)
+    nR = int(max(R for R, _, _ in o) + 1)
+    optical_topology = o
+
+    for i, j in s:
+        nx_static_topology.add_edge(i, j, weight=s[(i, j)])
+        nx_full_topology.add_edge(i, j, key=0, weight=s[(i, j)])
+    for r, i, j in o:
+        nx_full_topology.add_edge(i, j, key=r + 1, weight=o[(r, i, j)])
+    try:
+        solution = helper.get_objective(
+            __gain_update(nx_full_topology, nx_static_topology, D, optical_topology, nN, nR), D)
+
+    except ex as Exception:
+        return False, str(ex), ""
+
+    return True, "", solution

algorithms/heuristics/gain_update_undirected.py

+import copy
+import heuristics_helper_undirected as helper
+
+
+# not optimal if triangular inequality in optical links not respected
+def __gain_update(stopology, otopology, demand):
+    """
+    find the best graph for each demand
+    find the value of the objective function in each of these graphs
+    match the demand that got the smallest objective function
+    delete the demand
+    repeat everything until no more demand
+    """
+    s_topology = copy.deepcopy(stopology)
+    o_topology = copy.deepcopy(otopology)
+    s_temp = copy.deepcopy(s_topology)
+    o_temp = copy.deepcopy(o_topology)
+    pathlength = []
+    demands = []
+    current_obj_fct_value = -1
+    for (i, j) in demand:
+        demands += [[i, j]]
+    for k in range(len(demand)):
+        for i in demands:
+            (s_temp, o_temp) = helper.update_graph(s_temp, o_temp,
+                                                   helper.shortest_path(s_temp, o_temp, i[0], i[1], nN, nR)[0], False,
+                                                   nN, nR)
+            pathlength += [helper.get_objective(s_temp, demand, nN)]
+            s_temp = copy.deepcopy(s_topology)
+            o_temp = copy.deepcopy(o_topology)
+        min_distance = min(pathlength)
+        if min_distance == current_obj_fct_value:
+            return (s_topology)
+        else:
+            current_obj_fct_value = min_distance
+        min_index = pathlength.index(min_distance)
+        [path, distance] = helper.shortest_path(s_topology, o_topology, demands[min_index][0], demands[min_index][1],
+                                                nN, nR)
+        helper.update_graph(s_topology, o_topology, path, True, nN, nR)
+        del demands[min_index]
+        pathlength = []
+    return (s_topology)
+
+
+def solve(s, o, D):
+    ex = None
+    global nN
+    global nR
+    global optical_topology
+
+    all_arcs_ij = set([(i, j) for _, i, j in o])
+    all_arcs_ij.update(s)
+    nN = int(max(max(i, j) for i, j in all_arcs_ij) + 1)
+    nR = int(max(R for R, _, _ in o) + 1)
+    optical_topology = o
+
+    try:
+        solution = helper.get_objective(__gain_update(s, optical_topology, D), D, nN)
+    except ex as Exception:
+        return False, str(ex), ""
+
+    return True, "", solution

algorithms/heuristics/greedy_links_directed.py

+import networkx as nx
+import heuristics_helper_directed as helper
+
+
+def __greedy_links(G, nx_static, optical_topology, D, nN, nR):
+    obj_function_list = []
+    links = []
+    temp_static = nx_static.copy()
+    temp_G = G.copy()
+    current_obj_fct_value = -1
+    for (s, i, j) in optical_topology:
+        links += [(i, j)]
+    for k in range(len(links)):
+        for (i, j) in links:
+            if nx.shortest_path_length(temp_static, i, j, "weight") > nx.shortest_path_length(temp_G, i, j, "weight"):
+                temp_static = helper.update_graph(temp_G, temp_static, nx.shortest_path(G, i, j, "weight"), False,
+                                                  optical_topology, nN, nR)
+                obj_function_list += [helper.get_objective(temp_static, D)]
+            else:
+                obj_function_list += [helper.get_objective(temp_static, D)]
+            temp_static = nx_static.copy()
+            temp_G = G.copy()
+        min_distance = min(obj_function_list)
+        if min_distance == current_obj_fct_value:
+            return nx_static
+        else:
+            current_obj_fct_value = min_distance
+        min_index = obj_function_list.index(min_distance)
+        (start, end) = links[min_index]
+        if nx.shortest_path_length(nx_static, start, end, "weight") > nx.shortest_path_length(G, start, end, "weight"):
+            helper.update_graph(G, nx_static, nx.shortest_path(G, start, end, "weight"), True, optical_topology, nN, nR)
+        obj_function_list = []
+        links.remove((start, end))
+    return nx_static
+
+
+def solve(s, o, D):
+    ex = None
+    nx_full_topology = nx.MultiDiGraph()  # represents all currently possible edges
+    nx_static_topology = nx.MultiDiGraph()  # represents static edges and matching made
+
+    all_arcs_ij = set([(i, j) for _, i, j in o])
+    all_arcs_ij.update(s)
+    nN = int(max(max(i, j) for i, j in all_arcs_ij) + 1)
+    nR = int(max(R for R, _, _ in o) + 1)
+
+    for i, j in s:
+        nx_static_topology.add_edge(i, j, weight=s[(i, j)])
+        nx_full_topology.add_edge(i, j, key=0, weight=s[(i, j)])
+    for r, i, j in o:
+        nx_full_topology.add_edge(i, j, key=r + 1, weight=o[(r, i, j)])
+    try:
+        solution = helper.get_objective(
+            __greedy_links(nx_full_topology.copy(), nx_static_topology.copy(), o, D, nN, nR), D)
+
+    except ex as Exception:
+        return False, str(ex), ""
+
+    return True, "", solution

algorithms/heuristics/greedy_links_undirected.py

+import copy
+import heuristics_helper_undirected as helper
+
+
+# not optimal if triangular inequality in optical links not respected
+def __greedy_links(stopology, otopology, demand):  # this is really slow but can be made better see lower comment
+    """
+    match one optical link
+    find the value of the objective function in this new graph
+    repeat for all links
+    match the link that got the smallest objective function
+    repeat from the start until no more link
+    """
+    s_topology = copy.deepcopy(stopology)
+    o_topology = copy.deepcopy(otopology)
+    s_temp = copy.deepcopy(s_topology)
+    o_temp = copy.deepcopy(o_topology)
+    pathlength = []
+    links = []
+    current_obj_fct_value = -1
+    for (s, i, j) in o_topology:
+        links += [[i, j]]
+    for k in range(len(links)):
+        # instead of doing that it should be end when no more matches can be made not that hard but annoying
+        for i in links:
+            (s_temp, o_temp) = helper.update_graph(s_temp, o_temp,
+                                                   helper.shortest_path(s_temp, o_temp, i[