... between local federations and the target's list. Som

1
Selective Peering with Federations

• Michael Haberler, Otmar Lendl
• enum.at

2
Observations

• VSPs want IP-based interconnection
• Quality, cost, features,
• VSPs do not want to run open servers
• SPIT, DoS, CallerID, commercial reasons
• There will be a multitude of interconnection
  arrangements
• Private peerings
• GSMA, XConnect, IXP-affiliated
• Private networks, local arrangements, TLS-based
  communities,
• Carrier clubs vs. Enterprises
• Various settlement regimes
• P2P vs. DNS based

3
Definiton Federation

• A Group of VoIP Service Providers, that
• Accepts calls among each other
• Share a common administrative policy
• Share a common technical setup for
  interconnection
• NB VSP includes service providers, business
  users and potentially end users.
• Bilateral peerings, the open Internet, and P2P
  clouds are examples of federations.

4
Prediction

• There will be many federations.
• Its unlikely well see a single federation which
  connects all VSPs.
• If that single federation were open for
  everybody, were no better off than with RFC3263.
• If not open for all who will run it and decide
  who can join?

5
Direct peering (single hop)
Federation Y
Required federation discovery and
matching Call setup details are
intra-federation.

• A ?? B by rules of X
• D ?? A by rules of Z
• D,B,C to each other by rules of Y
• No federated path from A to C

6
Corollary 1

• There will be no full mesh of peerings between
  all VSPs.
• Thus not all calls can be completed via a direct
  call-setup between source and destination VSP.

7
Corollary 2

• If we want universal reachability without
  resorting to the PSTN
• There is a need for transit services.
• This is primarily about scaling, business and
  trust relationships
• On the SIP layer. Media can be direct.
• This is a competitive market.

8
Extending Federations to the Transit Case
Federation 1 (transit)
Federation 3
Federation 2
Transit SPs
C
A
B
Y
Z
X
Terminating SPs
9
Corollary 3

• If a number of VSPs provide transit services
  using various transit federations
• There is a need for a routing protocol.
• Find a route.
• Find the best route.
• All this under various contractual and
  business-related constraints

10
Problems and Solutions

• Is the target number on IP?
• To which federations is the target connected?
• Do we peer with each other?
• If not, who can I use as transit?
• How do I deliver the call?

Infrastructure ENUM
draft-lendl-speermint-federations
Intersection between local federations and the
targets list
Some off-list discussions, no clear way forward.
Federation-specific could be draft-penno-message-
flows
11
Implementation

• Mapping Domain to Federations
• draft-lendl-domain-policy-ddds-01
  draft-lendl-speermint-federations-01
• DDDS Application like ENUM
• Running Code
• A module is available for OpenSer
• See www.enum.at for code and documentation.
• Austrian I-ENUM Trial

12
Proposed structure for further work in SPEERMINT
WG

• Federation membership discovery and matching
  handles the direct peering scenario (subset of
  global connectivity)
• Implementation available feedback welcome
  http//www.enum.at/index.php?iddokumente
• consensus is the DNS-based approach the base
  for future work? OR can we assume SIP exchange is
  always/between all fabrics possible between
  non-Peers?
• should this become a WG item? Hum?
• Standards and BCPs on how federations operate
• Call flow I-Ds go here.
• Questions like To TLS or not (only) to TLS? go
  here.
• Addressing the transit scenarios global
  connectivity Routing across federations.
• The big elephant.. Is this in scope with WG
  charter?
• consensus on scenario requirements (double vs
  multiple transit)
• design team work