anchor.diff:  
   ==== Tx Scale to millions of flows
   
  -image::images/t_c5.png[title="TCP Tx side",align="left",width={p_width}, link="images/t_c5.png"]
  +image::images/t_c5.png[title="TCP Tx side",align="center",width={p_width}, link="images/t_c5.png"]
   
   Most TCP stacks have an API that allow the user to provide his buffer for write (push) and the TCP module will save them until the packets are acknowledged by the remote side. Figure 4 shows how one TX queue of one TCP flow looks like on the Tx side. This could create a scale issue in worst case. Let's assume we need 1M active flows with 64K TX buffer (with reasonable buffer, let's say RTT is small). The worst case buffer in this case could be
   1M x 64K * mbuf-factor (let's assume 2) = 128GB. The mbuf resource is expensive and needs to be allocated ahead of time.
  
positive.code:             
  ==== Simulation of latency/jitter/drop in high scale
  
  image::images/t_c7.png[title="TCP Rx side",align="left",width={p_width}, link="images/t_c7.png"]
  
  There is a requirement to simulate latency/jitter/drop in the network layer. Simulating drop in high rate it is not a problem, but simulating latency/jitter in high rate is a challenge because there is a need to queue a high number of packets. See figure 6 on the left.
  A better solution is to queue a pointer to both the TCP flow and the TCP descriptor (with TSO information) and only when needed (i.e. when it has already left the tx queue) build the packet again (lazy). The memory footprint in this case can be reduced dramatically.
  
negative.code: [bash]>./astf-sim -f astf/http_simple.py --full -o b.pcap 
  ----
  
  
  * Use `--full' initiated the full simulation mode
  * b.pcap output pcap file will be generated, it is the client side multiplex pcap
  * There is no server side pcap file in this simulation because we are not simulating latency/jitter/drop in this case so the server should be the same as client side.
  
  another example that will run sfr profile in release mode and will show the counters 
  
  [source,bash]
  ----
  [bash]>./astf-sim -f astf/sfr.py --full -o o.pcap -d 1 -r -v 
  ----
  
  
  
  === Traffic profile reference 
  