The University of Aberdeen Court

PREC (Prioritisation and Resilience for Emergency Communications) contributed to the MONROE project both by extending the network infrastructure and performing an extensive set of measurements exploring properties of IP-based wireless survivable networks.

PREC added new types of links to MONROE, including a satellite connection, a point-to-point radio link, and a narrow-band radio link. Also, two new mobile access links from UK operators, Vodafone™ and EE™, were made available from UoA-connected nodes. The new links helped to diversify the MONROE ecosystem, allowing traffic measurements on mixed high latency or low-rate networks as well as high speed 3G or LTE mobile links.

The MONROE platform was used as main testbed in various academic contributions carried out in PREC:

  • The possibility to deploy traffic classification in the Internet using DiffServ was explored through a measurement campaign in MONROE that investigated the pathologies associated to DiffServ Code Points (DSCPs). Access to MONROE nodes allowed comparison of results on mobile networks with results on wired-edge networks and the Internet core. The results were published in a Computer Communications journal paper [1]. A series of talks [2][3] on the topic were also carried out at the IETF to inform the debate about the definition of a new code-point for the Lower-Effort (LE) per hop behaviour (PHB).
  • Measurements collected on MONROE were used to analyse the Path MTU Discovery (PMTUD) algorithm presented at the Traffic Measurement Analysis Conference 2018 [5], and presented at the IETF MAP research group (19th July, 2018). This work highlights the need for a resilient method of determining Path MTU for non-TCP protocols and exploring mechanisms for mitigating this problem. The paper also forms the basis for work on PLPMTUD (Packetisation Layer PMTUD), a resilient method for discovering Path MTU, allowing robust fall back to a path with a lower PMTU. UoA is planning to use the PREC work as a basis for standardisation of new methods.
  • UoA also engaged with other MONROE partners to explore the implications of roaming on network performance within European mobile networks. This required coordination of seven European partners in order to deploy experiments, as well as work on data analysis dissemination. While work is still ongoing, a publication was already produced from the joint efforts that will appear at Mobicom 2018 [6].

PREC has also provided several significant contributions to the MONROE software base:

  • A Docker container including a traceroute-style tool using packet-forging library Scapy. The software was later extended into the stand-alone open-source tool Pathtrace [10]. The tool was described in a paper in Mobile Network Measurement workshop in June 2017 [9].
  • Various other Docker containers (open-source), packaging tools, such as edgetrace, ooniprobe and Netalyzr, used in the research on DSCP and PMTUD.
  • PREC contributed to the MONROE management system by creating monroe-cli, a Python library and a command line client to schedule efficiently experiments on the platform. This has received positive feedback from both MONROE researchers and developers. The tool is currently licenced under a BSD 2-clause licence and maintained under the MONROE Github repository [7]

Software release is available here:

[1] A. Custura, R. Secchi, G. Fairhurst, “Exploring DSCP Modification Pathologies in the Internet”, Comput. Comm., vol. 27, pp. 86-94, Sep. 2018.
[2] R. Secchi, “Measurement Concerning the DSCP for LE PHB”, IETF 99, Prague.
[3] G. Fairhurst, A. Custura, A. Venné, T. Jones, “LE codepoint: preliminary results and ongoing work in the IETF”, MAP Research Group, IRTF, Chicago, Mar. 2017.
[5] A. Custura, G. Fairhurst, I. Learmonth, “Exploring Usable Path MTU in the Internet”, in proc. of IFIP Network Traffic Measurement and Analysis (TMA) conference, paper 57, Apr 2018, Vienna.
[6] — , “Experience: Implications of Roaming in Europe”, to appear in ACM Mobicom 2018.
[7] A. Custura, “monroe-cli”, [online]:
[9] A. Custura, A. Venné, G. Fairhurst, “Exploring DSCP modifications pathologies in mobile edge network”, in proc. of Network Traffic Measurement (TMA) conference, June 2017, Dublin.
[10] A. Custura, “Docker images”, [online]: