Generating packets to test fragmentation

Abstract

Methods, apparatus and machine readable storage media for testing fragmentation of datagrams by a network under test. A traffic generator may generate a datagram including a header and a payload, the payload containing plural instrumentation blocks, each instrumentation block containing information identifying the datagram and information identifying the location of each instrumentation block within the datagram. The traffic generator may transmit the datagram over the network under test.

It is claimed: 
     
         1 . A method for testing fragmentation of datagrams by a network under test, comprising:
 a traffic generator generating a datagram including a header and a payload, the payload containing plural instrumentation blocks, each instrumentation block containing information identifying the datagram and information identifying the location of each instrumentation block within the datagram; and   the traffic generator transmitting the datagram over the network under test.   
     
     
         2 . The method of  claim 1 , wherein plural instrumentation blocks are disposed within the datagram such that, when the network under test converts the datagram into plural fragments, each fragment contains at least one complete instrumentation block. 
     
     
         3 . The method of  claim 2 , wherein
 an expected fragment payload length is known, and   generating the datagram further comprises inserting plural instrumentation blocks into the datagram at intervals equal to the expected fragment payload length.   
     
     
         4 . The method of  claim 2 , wherein
 a minimum fragment payload length is known, and   generating the datagram further comprises inserting plural instrumentation blocks into the datagram at intervals less than or equal to one-half of the minimum fragment payload length.   
     
     
         5 . The method of  claim 1 , wherein the information identifying the datagram includes a packet group identifier and a packet sequence number. 
     
     
         6 . The method of  claim 1  wherein the information identifying the location of the instrumentation block within the datagram includes at least one of an instrumentation block sequence number and an instrumentation block offset. 
     
     
         7 . The method of  claim 1 , wherein each of the plural instrumentation blocks contains information indicating at least one of a total number of instrumentation blocks within the datagram and a payload length of the datagram. 
     
     
         8 . The method of  claim 1 , further comprising:
 a packet receiver receiving, from the network under test, a plurality of fragments derived from the datagram;   the packet receiver determining if the received fragments constitute the complete datagram based, at least in part, on data within respective instrumentation blocks extracted from each received fragment; and   the packet receiver accumulating and reporting test statistics indicative of a number of complete datagrams received and a number of incomplete datagrams received.   
     
     
         9 . The method of  claim 1 , further comprising:
 a packet receiver receiving the datagram after the datagram has been fragmented and reassembled by the network under test;   the packet receiver determining if the received datagram has been corrected reassembled based on instrumentation blocks extracted from the payload of the received datagram; and   the packet receiver accumulating and reporting test statistics indicative of a number of correctly reassembled datagrams received and a number of incorrectly reassembled datagrams received.   
     
     
         10 . An apparatus for testing fragmentation of datagrams by a network under test, comprising:
 a traffic generator configured to:
 generate a datagram including a header and a payload, the payload containing plural instrumentation blocks, each instrumentation block containing information identifying the datagram and information identifying the location of each instrumentation block within the datagram; and 
 transmit the datagram over the network under test. 
   
     
     
         11 . The apparatus of  claim 10 , wherein plural instrumentation blocks are disposed within the datagram such that, when the network under test converts the datagram into plural fragments, each fragment contains at least one complete instrumentation block. 
     
     
         12 . The apparatus of  claim 11 , wherein
 an expected fragment payload length is known, and   the traffic generator is configured to insert plural instrumentation blocks into datagrams at intervals equal to the expected fragment payload length.   
     
     
         13 . The apparatus of  claim 11 , wherein
 a minimum fragment payload length is known, and   the traffic generator is configured to insert plural instrumentation blocks into datagrams at intervals less than or equal to one-half of the minimum fragment payload length.   
     
     
         14 . The apparatus of  claim 10 , wherein the information identifying the datagram includes a packet group identifier and a packet sequence number. 
     
     
         15 . The apparatus of  claim 10  wherein the information identifying the location of the instrumentation block within the datagram includes at least one of an instrumentation block sequence number and an instrumentation block offset. 
     
     
         16 . The apparatus of  claim 10 , wherein each of the plural instrumentation blocks contains information indicating at least one of the total number of instrumentation blocks within the datagram and the payload length of the datagram. 
     
     
         17 . The apparatus of  claim 10 , further comprising:
 a packet receiver configured to:
 receive, from the network under test, a plurality of fragments derived from the datagram; 
 determine if the received fragments constitute the complete datagram based, at least in part, on data within respective instrumentation blocks extracted from each received fragment; and 
 accumulate and report test statistics indicative of a number of complete datagrams received and a number of incomplete datagrams received. 
   
     
     
         18 . The apparatus of  claim 10 , further comprising:
 a packet receiver configured to:
 receive the datagram after the datagram has been fragmented and reassembled by the network under test; 
 determine if the received datagram has been corrected reassembled based on instrumentation blocks extracted from the payload of the received datagram; and 
 accumulate and report test statistics indicative of a number of correctly reassembled datagrams received and a number of incorrectly reassembled datagrams received. 
   
     
     
         19 . A non-transitory machine readable storage media containing configuration data which, when used to configure a programmable hardware device, causes the programmable hardware device to be configured to include:
 a traffic generator configured to:
 generate a datagram including a header and a payload, the payload containing plural instrumentation blocks, each instrumentation block containing information identifying the datagram and information identifying the location of each instrumentation block within the datagram; and 
 transmit the datagram over a network under test. 
   
     
     
         20 . The non-transitory machine readable storage media of  claim 19 , wherein plural instrumentation blocks are disposed within the datagram such that, when the network under test converts the datagram into plural fragments, each fragment contains at least one complete instrumentation block. 
     
     
         21 . The non-transitory machine readable storage media of  claim 20 , wherein
 an expected fragment payload length is known, and   the traffic generator is configured to insert plural instrumentation blocks into datagrams at intervals equal to the expected fragment payload length.   
     
     
         22 . The non-transitory machine readable storage media of  claim 20 , wherein
 a minimum fragment payload length is known, and   the traffic generator is configured to insert plural instrumentation blocks into datagrams at intervals less than or equal to one-half of the minimum fragment payload length.   
     
     
         23 . The non-transitory machine readable storage media of  claim 19 , wherein the information identifying the datagram includes a packet group identifier and a packet sequence number. 
     
     
         24 . The non-transitory machine readable storage media of  claim 19 , wherein the information identifying the location of the instrumentation block within the datagram includes at least one of an instrumentation block sequence number and an instrumentation block offset. 
     
     
         25 . The non-transitory machine readable storage media of  claim 19 , wherein each of the plural instrumentation blocks contains information indicating at least one of the total number of instrumentation blocks within the datagram and the payload length of the datagram. 
     
     
         26 . The non-transitory machine readable storage media of  claim 19 , wherein the programmable hardware device is configured to further include:
 a packet receiver configured to:
 receive, from the network under test, a plurality of fragments derived from the datagram; 
 determine if the received fragments constitute the complete datagram based, at least in part, on data within respective instrumentation blocks extracted from each received fragment; and 
 accumulate and report test statistics indicative of a number of complete datagrams received and a number of incomplete datagrams received. 
   
     
     
         27 . The non-transitory machine readable storage media of  claim 19 , wherein the programmable hardware device is configured to further include:
 a packet receiver configured to:
 receive the datagram after the datagram has been fragmented and reassembled by the network under test; 
 determine if the received datagram has been corrected reassembled based on instrumentation blocks extracted from the payload of the received datagram; and 
 accumulate and report test statistics indicative of a number of correctly reassembled datagrams received and a number of incorrectly reassembled datagrams received.