A method comprising: receiving, for each of multiple network devices distributed throughout a geographic region, at least one measured performance characteristic value corresponding to that network device; identifying device groups based on evaluations of the received measured performance characteristic values, wherein each device group: has a different subset of the multiple network devices as members and has at least two members, is identified at least in part based on determined locations of the group members within the geographic region, and is identified at least in part based on the received measured performance characteristic values, corresponding to the group members, meeting at least one pre-established criterion, wherein identifying the device groups comprises: (a) selecting one of the multiple network devices as a focus device, (b) identifying others of the multiple network devices located proximate to the focus device, (c) evaluating the received measured performance characteristic values corresponding to the focus device and the devices identified in step (b), (d) classifying the focus device and the devices identified in step (b) as a problem device grouping based on the evaluations of step (c), (e) performing additional iterations of steps (a) through (d), wherein in each iteration a different one of the multiple network devices is selected as the focus device, and (f) identifying a device group by combining the problem device groupings identified in separate performances of step (d) and having common members; and communicating information about the identified device groups. receiving, for each of multiple network devices distributed throughout a geographic region, at least one measured performance characteristic value corresponding to that network device; identifying device groups based on evaluations of the received measured performance characteristic values, wherein each device group: has a different subset of the multiple network devices as members and has at least two members, is identified at least in part based on determined locations of the group members within the geographic region, and is identified at least in part based on the received measured performance characteristic values, corresponding to the group members, meeting at least one pre-established criterion, wherein identifying the device groups comprises: (a) selecting one of the multiple network devices as a focus device, (b) identifying others of the multiple network devices located proximate to the focus device, (c) evaluating the received measured performance characteristic values corresponding to the focus device and the devices identified in step (b), (d) classifying the focus device and the devices identified in step (b) as a problem device grouping based on the evaluations of step (c), (e) performing additional iterations of steps (a) through (d), wherein in each iteration a different one of the multiple network devices is selected as the focus device, and (f) identifying a device group by combining the problem device groupings identified in separate performances of step (d) and having common members; and communicating information about the identified device groups. has a different subset of the multiple network devices as members and has at least two members, is identified at least in part based on determined locations of the group members within the geographic region, and is identified at least in part based on the received measured performance characteristic values, corresponding to the group members, meeting at least one pre-established criterion, wherein identifying the device groups comprises: (a) selecting one of the multiple network devices as a focus device, (b) identifying others of the multiple network devices located proximate to the focus device, (c) evaluating the received measured performance characteristic values corresponding to the focus device and the devices identified in step (b), (d) classifying the focus device and the devices identified in step (b) as a problem device grouping based on the evaluations of step (c), (e) performing additional iterations of steps (a) through (d), wherein in each iteration a different one of the multiple network devices is selected as the focus device, and (f) identifying a device group by combining the problem device groupings identified in separate performances of step (d) and having common members; and communicating information about the identified device groups. (a) selecting one of the multiple network devices as a focus device, (b) identifying others of the multiple network devices located proximate to the focus device, (c) evaluating the received measured performance characteristic values corresponding to the focus device and the devices identified in step (b), (d) classifying the focus device and the devices identified in step (b) as a problem device grouping based on the evaluations of step (c), (e) performing additional iterations of steps (a) through (d), wherein in each iteration a different one of the multiple network devices is selected as the focus device, and (f) identifying a device group by combining the problem device groupings identified in separate performances of step (d) and having common members; and