Ppp terminating equipment, network equipment and method of responding to lcp echo requirement

Abstract

In a PPP terminating equipment 100 connected with a switch fabric and terminating PPP link, the PPP terminating equipment 100 has an LCP echo requirement detecting section 20 detecting whether or not a received packet is the LCP echo requirement packet, and an LCP echo response producing section 40 producing a response packet to the LCP echo requirement by rewriting the LCP header of the received LCP echo requirement packet. The PPP terminating equipment 100 thereby produces and returns the response packet to the LCP echo requirement.

1 - 16 . (canceled) 
     
     
         17 . A method comprising:
 determining that a first packet, received at a network device, is a Link Control Protocol (LCP) echo requirement packet;   determining that the first packet was sent by the network device; and   discarding, in response to determining that the first packet is the LCP echo requirement packet and that the first packet was sent by the network device, the first packet without producing an LCP echo response packet for the first packet.   
     
     
         18 . The method of  claim 17 , where determining that the first packet was sent by the network device includes:
 extracting a number from the first packet, and   determining that the extracted number corresponds to a second number associated with the network device.   
     
     
         19 . The method of  claim 17 , further comprising:
 receiving a second packet that includes flag information, the flag information indicating whether an LCP echo response packet is to be produced;   extracting the flag information from the second packet;   determining that the flag information indicates that the LCP echo response packet is to be produced; and   producing the LCP echo response packet, for the second packet, based on the extracted flag information.   
     
     
         20 . The method of  claim 19 , where the second packet is received from a switch fabric, the method further comprising:
 sending the LCP echo response packet toward a destination external to the network device.   
     
     
         21 . The method of  claim 17 , where determining that the first packet is the LCP echo requirement packet includes:
 determining that a header of the first packet includes a particular value, where the particular value identifies the first packet as comprising the LCP requirement packet.   
     
     
         22 . The method of  claim 17 , where determining that the first packet was sent by the network device includes:
 extracting a number from the first packet; and   determining that the extracted number does not correspond to a second number associated with the network device.   
     
     
         23 . The method of  claim 22 , where extracting the number includes:
 extracting the number from a header of the first packet, and   where the second number is predetermined by the network device.   
     
     
         24 . A method comprising:
 extracting, from a packet received at a network device, flag information from the packet, the flag information indicating whether a Link Control Protocol (LCP) echo response packet is to be produced;   determining, by the network device, that the extracted flag information indicates that the LCP echo response packet is to be produced; and   producing, by the network device, the LCP echo response packet, for the first packet, based on the extracted flag information.   
     
     
         25 . The method of  claim 24 , further comprising:
 receiving the packet from a switch fabric of the network device; and   transmitting, the LCP echo response packet toward a destination.   
     
     
         26 . The method of  claim 24 , where producing the LCP echo response packet includes:
 modifying a value of a header of the packet to produce the LCP echo response packet.   
     
     
         27 . The method of  claim 24 , where determining that the extracted flag information indicates that the LCP echo response packet is to be produced includes:
 extracting a number from the packet; and   determining that the extracted number does not correspond to a second number associated with the network device.   
     
     
         28 . The method of  claim 27 , where extracting the number includes:
 extracting the number from a header of the packet, and   where the second number is predetermined by the network device.   
     
     
         29 . The method of  claim 28 , further comprising:
 writing the second number into a field of the header.   
     
     
         30 . A network device comprising:
 a switch fabric; and   Point-to-Point (PPP) terminating equipment to:
 determine that a first packet, received at the network device, is a Link Control Protocol (LCP) echo requirement packet, 
 determine that the first packet was sent by the network device, and 
 discard, in response to determining that the first packet is the LCP echo requirement packet and that the first packet was sent by the network device, the first packet without producing an LCP echo response packet for the first packet. 
   
     
     
         31 . The network device of  claim 30 , where, when determining that the first packet was sent by the network device, the PPP terminating equipment is further to:
 extract a number from the first packet, and   determine that the extracted number corresponds to a second number associated with the network device.   
     
     
         32 . The network device of  claim 30 , where the PPP terminating equipment is further to:
 receive a second packet that includes flag information, the flag information indicating whether an LCP echo response packet is to be produced,   extract the flag information from the second packet,   determine that the flag information indicates that the LCP echo response packet is to be produced, and   produce the LCP echo response packet, for the second packet, based on the extracted flag information.   
     
     
         33 . The network device of  claim 32 , where the second packet is received from the switch fabric, and the PPP terminating equipment is further to:
 send the LCP echo response packet toward a destination.   
     
     
         34 . The network device of  claim 30 , where, when determining that the first packet is the LCP echo requirement packet, the PPP terminating equipment is further to:
 determine that a header of the first packet includes a particular value, where the particular value identifies the first packet as comprising the LCP requirement packet.   
     
     
         35 . The network device of  claim 30 , where, when determining that the first packet was sent by the network device, the PPP terminating equipment is further to:
 extract a number from the first packet; and   determine that the extracted number does not correspond to a second number associated with the network device.   
     
     
         36 . The network of  claim 35 , where, when extracting the number, the PPP terminating section is further to:
 extract the number from a header of the first packet, and   where the second number is predetermined by the network device.