OWAMP One-Way Active Measurement Protocol (Sample Implementation) Jeff Boote Internet2 18 November 2018

What is it? A control protocol A test protocol A sample implementation of both 11/18/2018

Why the OWAMP protocol? There have been many implementations to do OWD over the years (Surveyor, Ripe…) The real problem is interoperability. The solution is standards. 11/18/2018

OWAMP Protocol Now possible due to growing availability of good time sources Wide deployment of “open” servers could allow measurement of one-way delay to become as commonplace as measurement of RTT using ICMP tools such as ping. Current Draft: http://www.ietf.org/internet-drafts/draft-ietf-ippm-owdp-07.txt Sample implementation available 11/18/2018

OWAMP Control protocol Supports authentication and authorization (encryption possible) Used to request tests Used to start/stop tests Used to retrieve results 11/18/2018

OWAMP Test protocol Endpoint controlled port numbers Extremely configurable send schedule Configurable packet sizes Packets can be “clear”, “authenticated”, or “Encrypted” Provisions for dealing with partial session results 11/18/2018

Sample Implementation Applications owampd daemon owping client Built upon protocol abstraction library Supports one-off applications Allows authentication/policy hooks to easily be incorporated 11/18/2018

Functionality (owping client) owping client application communicates with the “other” endpoint of the test Communication can be “open”, “authenticated”, or “encrypted” Requests include a full parameterization of the test OWD tests can be in either direction Supports the setup of many tests concurrently Supports the buffering of results on the server for later retrieval 11/18/2018

Functionality (owampd) Accepts requests for OWD tests including start time and parameters for test Responds with accepted/denied Tests are formally started with a StartSessions message from the client. (start times in the past are adjusted to “current time”) Runs tests Sessions “toward” the server are saved for retrieval Can add a timeout so that “start session” message must be received within a given timeout to thwart DOS 11/18/2018

Resource Allocation Model Spheres of control Is the basic parameterization of the requested test allowed? Does the owampd have enough resources to allow test? Does this host have enough resources? Does this <higher level…> have enough resources? 11/18/2018

Resource Allocation (owampd) Each connection is “classified” (authentication) Each classification is associated with a set of hierarchical limits owampd.limits (no time dependant dimension to resource allocation in owampd) 11/18/2018

Architecture 11/18/2018

Specific difficulties Time: Operational issues predominate Determining an accurate timestamp “error” is in many ways more difficult than getting a “very good” timestamp Working as an “open” server requires UTC time source (For predefined test peers, other options available) Firewalls: Port filter trade-off Administrators like pre-defined port numbers Vendor manufactures would probably like to “prioritize” test traffic 11/18/2018

Future Steps Administrator specified port ranges for “test” traffic Support “partial results” protocol extensions Open source development 11/18/2018

Availability http://e2epi.internet2.edu/owamp/ Currently available Mail lists: owamp-users@internet2.edu owamp-announce@internet2.edu https://mail.internet2.edu/wws/lists/engineering 11/18/2018