OWAMP

1
OWAMP

• One-Way Active Measurement Protocol (Sample
  Implementation)
• Jeff Boote
• Internet2

2
What is it?

• A control protocol
• A test protocol
• A sample implementation of both

3
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.

4
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 Drafthttp//www.ietf.org/internet-drafts
  /draft-ietf-ippm-owdp-07.txt
• Sample implementation available

5
OWAMP Control protocol

• Supports authentication and authorization
  (encryption possible)
• Used to request tests
• Used to start/stop tests
• Used to retrieve results

6
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

7
Sample Implementation

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

8
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

9
Functionality (owampd)

• 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

10
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 lthigher levelgt have enough resources?

11
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)

12
Architecture
13
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

14
Future Steps

• Administrator specified port ranges for test
  traffic
• Support partial results protocol extensions
• Open source development

15
Availability

• Currently available
• http//e2epi.internet2.edu/owamp/
• Mail lists
• owamp-users_at_internet2.edu
• owamp-announce_at_internet2.edu
• https//mail.internet2.edu/wws/lists/engineering