NAME

       mm-link - UNIX shell connected to an emulated link with a user-specified packet-delivery schedule.

SYNOPSIS

       mm-link uplink downlink [-- command...]

DESCRIPTION

       mm-link is a network emulation tool that emulates links using packet delivery trace files (uplink for the
       uplink direction and downlink for the downlink direction) provided on  the  command  line.  mm-link  uses
       clone(2)  to  fork a new shell in a distinct network namespace.  uplink_trace_file emulates the link from
       mm-link to the Internet and downlink_trace_file emulates the link from the Internet to mm-link.

       mm-link can emulate both time-varying links, such as cellular links, and links with  fixed  link  speeds.
       When a packet arrives at the link (from either the Internent or from mm-link), it is directly placed into
       one of two packet queues depending on its intended direction: the uplink queue  or  the  downlink  queue.
       mm-link releases packets from each queue based on the corresponding input packet-delivery trace.

       Each  line  in the trace  represents a packet delivery opportunity: the time at which an MTU-sized packet
       can be delivered in the emulation. Accounting is done at the byte-level, and  each  delivery  opportunity
       represents  the ability to deliver 1500 bytes. Thus, a single line in the trace file can delivery several
       smaller packets whose sizes sum to 1500 bytes. Delivery opportunities are wasted if bytes are unavailable
       at the instant of an opportunity. When mm-link reaches the end of an input trace file, it wraps around to
       the beginning of the trace file. mm-link can be nested within delayshell (1)  to  flexibly  create  links
       with a user-supplied one-way delay and a user-supplied link rate.

       To exit mm-link, simply type "exit" or CTRL-D inside mm-link.

EXAMPLE

       To emulate a 12 Mbit/s link (in each direction), make a 12 Mbit/s
       tracefile, "12Mbps_trace". This file can be of arbitrary length
       and must follow the pattern below:
       0
       1
       2
       3
       4
       5...
       The link above delivers an MTU-sized packet (1500 bytes or 12000 bits) every
       ms.

       Run mm-link with:
       $ mm-link 12Mbps_trace 12Mbps_trace

       All programs run from within mm-link are sent according
       to the packet delivery times specified in 12Mbps_trace.

       mm-link
       [...] (copyright notice omitted)

SEE ALSO

       mahimahi(1), mm-delay(1), mm-webrecord(1), mm-webreplay(1).

       Project home page: http://mahimahi.mit.edu

AUTHOR

       Mahimahi  was  written  by  Ravi  Netravali, Anirudh Sivaraman, Greg D. Hill, Deepak Narayanan, and Keith
       Winstein.

BUGS

       Please report bugs to mahimahi@mit.edu.

                                                  February 2014                                       mm-link(1)