Communications device and method of operating a communications device that continues to connect local users after a link fails

Abstract

A next-generation network utilizes a three-tier, cascading fault approach to providing emergency stand-alone (ESA) switching in a circuit-to-packet (C2P) network. Calls that are placed to destination numbers which are connected to the same local network device are completed even when connectivity with a community network level has been interrupted, while calls that are placed to destination numbers which are connected to the same community are completed even when connectivity with a gateway media controller has been interrupted.

1 . A communications device comprising: 
 a memory to store a plurality of dialed numbers; and    a state machine connected to the memory, the state machine to determine a link status after a dialed number has been received, determine whether the dialed number is stored in the memory when the link status indicates that a link is unavailable, command that an indication be output that a connection can not be made at this time when the dialed number is absent from the memory and the link status indicates that the link is unavailable, and command that a connection be made between a first user device and a second user device when the dialed number is one of the plurality of dialed numbers stored in the memory and the link status indicates that the link is unavailable.    
   
   
       2 . The communications device of  claim 1  wherein the first user device generates the dialed number, and the dialed number identifies the second user device.  
   
   
       3 . The communications device of  claim 1  and further comprising a switching circuit connected to the state machine, the switching circuit to make the connection between the first user device and the second user device.  
   
   
       4 . The communications device of  claim 3  wherein the switching circuit is a local circuit directly connected to a plurality of user devices, the plurality of user devices including the first and second user devices.  
   
   
       5 . The communications device of  claim 4  wherein a user device of the plurality of user devices is an xDSL device.  
   
   
       6 . The communications device of  claim 3  wherein the switching circuit is a community circuit that is connected to a plurality of user devices by way of a network device, the plurality of user devices including the first and second user devices.  
   
   
       7 . The communications device of  claim 6  wherein a user device of the plurality of user devices is an xDSL device.  
   
   
       8 . A communications device comprising: 
 a local switching circuit to be directly connected to a plurality of user devices; and    a state machine connected to the local switching circuit, the state machine to determine a link status after a dialed number has been received from a first user device of the plurality of user devices, command the local switching circuit to output an indication to the first user device that a connection can not be made at this time when the dialed number does not represent one of the plurality of user devices and the link status indicates that a link is unavailable, and command the local switching circuit to make a connection between the first user device and a second user device when the dialed number represents one of the plurality of user devices and the link status indicates that the link is unavailable.    
   
   
       9 . The communications device of  claim 8  wherein the dialed number identifies the second user device.  
   
   
       10 . The communications device of  claim 9  and further comprising a memory connected to the state machine, the memory to store a plurality of user numbers, the plurality of user numbers representing the plurality of user devices.  
   
   
       11 . The communications device of  claim 10  wherein the state machine determines whether the dialed number matches a user number stored in the memory.  
   
   
       12 . A method of operating a communications device comprising: 
 detecting a dialed number that was generated by a first user device, the dialed number identifying a second user device;    determining a link status;    commanding that an indication be output to the first user device that a connection can not be made at this time when the first user device is connected by way of one of a number of downstream links, the second user device is connected by way of an upstream link, and the link status indicates that the upstream link is unavailable; and    commanding that a connection be made between the first user device and the second user device when the first user device is connected by way of one of the number of downstream links, the second user device is connected by way of one of the number of downstream links, and the link status indicates that the upstream link is unavailable.    
   
   
       13 . The method of  claim 12  and further comprising commanding that the dialed number be forwarded to a network device.  
   
   
       14 . The method of  claim 13  wherein the link status is determined by reading a register, the register being set to indicate that the upstream link is unavailable when no message has been received from the network device for a predetermined time out period.  
   
   
       15 . The method of  claim 13  and further comprising detecting whether forwarding information has been received from the network device in response to forwarding the dialed number to the network device.  
   
   
       16 . The method of  claim 15  and further comprising commanding that a connection be made between the first user device and the second user device when forwarding information has been received from the network device in response to forwarding the dialed number to the network device.  
   
   
       17 . A method of operating a communications device comprising: 
 determining a link status after a dialed number has been received from one of a plurality of user devices;    commanding that an indication be output that a connection can not be made at this time when the dialed number does not represent one of the plurality of user devices and the link status indicates that a link is unavailable, and    commanding that a connection be made between a first user device and a second user device when the dialed number represents one of the plurality of user devices and the link status indicates that the link is unavailable.    
   
   
       18 . The method of  claim 17  and further comprising determining whether the dialed number is stored in a memory when the link status indicates that the link is unavailable, the memory storing a plurality of user numbers, the plurality of user numbers representing the plurality of user devices.  
   
   
       19 . The method of  claim 17  and further comprising commanding that the dialed number be forwarded to a network device.  
   
   
       20 . The method of  claim 19  wherein the link status is determined by reading a register, the register to be set to indicate that the link in unavailable when no message has been received from the network device for a predetermined time out period.  
   
   
       21 . The method of  claim 20  and further comprising detecting whether forwarding information has been received from the network device in response to forwarding the dialed number to the network device.  
   
   
       22 . The method of  claim 21  and further comprising commanding that a connection be made between the first user device and the second user device when forwarding information has been received from the network device in response to forwarding the dialed number to the network device.