All things related to multicast

[Alex Hsia <>]

Bill-

thanks for the update.  I've been trying to get the Okeanos folks to transition to SSM for some time now.  They are aware of the deadline and are now more motivated to get their stream transitioned.

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On Wed, Sep 26, 2018 at 9:00 AM Bill Owens <> wrote:

Many of you will have seen this from I2 on other lists, but I thought it would be good to post it here as well.

The only active multicast user I’m aware of within NYSERNet is a faculty member who participates with the Okeanos Explorer project, which is in port right now but will be heading out for another mission in October. I’m going to contact them and let them know that unless the folks who provide the multicast stream change it to SSM, it will become unavailable before the end of this year. 

If anybody else is aware of active multicast apps, now would be the time to push for transition...

Bill.

---

From: Chris Robb <>
Sent: Wednesday, September 26, 2018 10:49:12 AM
To:
Subject: A special and important note regarding ASM multicast sunsetting

 

(PLEASE NOTE this is a special announcement from Internet2 regarding the eventual turndown of a service. It should be passed along to the appropriate engineering staff within your organization to determine impact.)

To the appropriate technical personnel:

Internet2, in response to community recommendations, IETF recommendations, as well as interoperability concerns with future growth, will begin the sunset of Interdomain Any Source Multicast (ASM).

As part of this transition, Internet2 will coordinate with members to begin the decommission of MSDP peerings.  This has already been occurring with various members and we are seeing an accelerated trend since the release of IETF draft-acg-mboned-deprecate-interdomain-asm-01 (https://tools.ietf.org/id/draft-acg-mboned-deprecate-interdomain-asm-01.html)  Internet2 is recommending that for the few members that still have active ASM sources, to transition these to SSM.  If this is technically impractical, our technical staff can work with your organization and your multicast subscribers to transition to private multicast peerings, such as layer 2 circuits between receivers, and/or the provisioning of private multicast VPNs (mvpns) between participants.  Internet2 will be available for feedback and questions during the 2018 Techex, October 15th 2018. Starting on October 28, Internet2 will begin formally sending notification to any existing MSDP peers that a disconnect will be scheduled. We hope to have all MSDP sessions removed by Dec 15th, 2018.

Background:

There are two well known flavors of IP multicast: Any Source Multicast (ASM), and Source Specific Multicast (SSM).  Initially, many applications were written to leverage ASM addressing. This was mostly due to the fact that several operating systems lacked support for IGMPv3, a necessary component of SSM.  As such, autonomous network would exchange information using the Multicast Source Discovery Protocol, or MSDP. MSDP was implemented in 2003 and has remained in “experimental” status. The low demand across operators for this feature has led to deficiencies which have not been addressed, leading to liabilities on the Internet2 network.  These deficiencies include flooding of network state information, lack of state attack protection, and undesired source filtering.

As time progressed, it became clear that the use case for ASM was not as relevant in the interdomain setting.  That is, between domains, usually only one source would send data to multiple receivers, something better suited to SSM.  Major operating systems have also been supporting SSM for time (Windows, MacOS, Linux/Android). As Internet2 continues to evolve it’s network, it became clear that our continued support of MSDP would hinder future growth, in part by the lack of attention the protocol has received from vendors, resulting in the deficiencies listed above.  In response, the IETF felt it necessary to issue a draft BCP recommending the deprecation of Inter-domain ASM (draft-acg-mboned-deprecate-interdomain-asm-01). Internet2 supports the IETF draft and believes this is the best path forward for the community.

Please note that this does NOT mean that Internet2 will stop supporting Interdomain Multicast; PIM SSM and IPv6 will both be supported mechanisms for interdomain multicast applications across the Internet2 footprint.  

Sincerely,

Internet2 Architecture and Engineering