Multicast traffic % in enterprise network ?
Hi Every one, Recently we had good discussion over multicast uses in public internet. From discussion, it was pointed out uses of multicast is more with in enterprise. Wanted to understand how much % multicast traffic present in network * If there is any data which can provide what % of traffic is multicast traffic. And if multicast is removed, how much unicast traffic it would add up? * Since this forum has people from deployment area, I would love to know if there is real deployment problems or its pain to deploy multicast. These questions is to work / discussion in IETF to see what is pain points for multicast, and how can we simplify it. Thanks Mankamana
I believe multicast is only used for IPTV Multicast by itself does not reduce much bandwidth : that reduction is purely based on the network design If you place unicast nodes near your customers, multicast is effectively unicast (just think about it) :) On 08/08/2018 08:49 PM, Mankamana Mishra (mankamis) via NANOG wrote:
Hi Every one, Recently we had good discussion over multicast uses in public internet. From discussion, it was pointed out uses of multicast is more with in enterprise. Wanted to understand how much % multicast traffic present in network
* If there is any data which can provide what % of traffic is multicast traffic. And if multicast is removed, how much unicast traffic it would add up? * Since this forum has people from deployment area, I would love to know if there is real deployment problems or its pain to deploy multicast.
These questions is to work / discussion in IETF to see what is pain points for multicast, and how can we simplify it.
Thanks Mankamana
On Aug 8, 2018, at 3:29 PM, nanog@jack.fr.eu.org<mailto:nanog@jack.fr.eu.org> wrote: I believe multicast is only used for IPTV There is at least one company that is using multicast for video switching, or in other words to replace HDMI switchers in rooms with video sources and displays. They have devices that encode video from an HDMI input to a multicast stream. And devices that receive a multicast stream and output the video from that stream to an HDMI output. So you can have multiple cameras and a multicast stream for each camera is input into the network. Then you can have a projector that can choose any of those multicast streams to display. I believe the video is uncompressed Multicast by itself does not reduce much bandwidth : that reduction is purely based on the network design If you place unicast nodes near your customers, multicast is effectively unicast (just think about it) :) On 08/08/2018 08:49 PM, Mankamana Mishra (mankamis) via NANOG wrote: Hi Every one, Recently we had good discussion over multicast uses in public internet. From discussion, it was pointed out uses of multicast is more with in enterprise. Wanted to understand how much % multicast traffic present in network * If there is any data which can provide what % of traffic is multicast traffic. And if multicast is removed, how much unicast traffic it would add up? * Since this forum has people from deployment area, I would love to know if there is real deployment problems or its pain to deploy multicast. These questions is to work / discussion in IETF to see what is pain points for multicast, and how can we simplify it. Thanks Mankamana --- Bruce Curtis bruce.curtis@ndsu.edu<mailto:bruce.curtis@ndsu.edu> Certified NetAnalyst II 701-231-8527 North Dakota State University
As someone else remarked, part of this will depend on the type of network you are profiling. One enterprise networking may have critical internal applications that depend on multicast to work and others may have nothing but the basic requirements of the network itself (e.g. IPv6 uses multicast instead of broadcast for some network control information distribution). On Wed, Aug 8, 2018 at 11:49 AM, Mankamana Mishra (mankamis) via NANOG < nanog@nanog.org> wrote:
Hi Every one, Recently we had good discussion over multicast uses in public internet. From discussion, it was pointed out uses of multicast is more with in enterprise. Wanted to understand how much % multicast traffic present in network
* If there is any data which can provide what % of traffic is multicast traffic. And if multicast is removed, how much unicast traffic it would add up? * Since this forum has people from deployment area, I would love to know if there is real deployment problems or its pain to deploy multicast.
These questions is to work / discussion in IETF to see what is pain points for multicast, and how can we simplify it.
Thanks Mankamana
Financial exchanges around the world use multicast. On Wed, Aug 8, 2018 at 1:31 PM, Stan Barber <sob@academ.com> wrote:
As someone else remarked, part of this will depend on the type of network you are profiling. One enterprise networking may have critical internal applications that depend on multicast to work and others may have nothing but the basic requirements of the network itself (e.g. IPv6 uses multicast instead of broadcast for some network control information distribution).
On Wed, Aug 8, 2018 at 11:49 AM, Mankamana Mishra (mankamis) via NANOG < nanog@nanog.org> wrote:
Hi Every one, Recently we had good discussion over multicast uses in public internet. From discussion, it was pointed out uses of multicast is more with in enterprise. Wanted to understand how much % multicast traffic present in network
* If there is any data which can provide what % of traffic is multicast traffic. And if multicast is removed, how much unicast traffic it would add up? * Since this forum has people from deployment area, I would love to know if there is real deployment problems or its pain to deploy multicast.
These questions is to work / discussion in IETF to see what is pain points for multicast, and how can we simplify it.
Thanks Mankamana
Multicast was also required for earlier versions of VXLAN. But later versions or VXLAN only require unicast. For the far future it seems like Named Data Neworking, Content Centric Networking, Information Centric Networking, Data Centric Networking etc all list multicast as a requirement or fundamental part of their architecture.
On Aug 8, 2018, at 4:15 PM, Greg Shepherd <gjshep@gmail.com> wrote:
Financial exchanges around the world use multicast.
On Wed, Aug 8, 2018 at 1:31 PM, Stan Barber <sob@academ.com> wrote:
As someone else remarked, part of this will depend on the type of network you are profiling. One enterprise networking may have critical internal applications that depend on multicast to work and others may have nothing but the basic requirements of the network itself (e.g. IPv6 uses multicast instead of broadcast for some network control information distribution).
On Wed, Aug 8, 2018 at 11:49 AM, Mankamana Mishra (mankamis) via NANOG < nanog@nanog.org> wrote:
Hi Every one, Recently we had good discussion over multicast uses in public internet. From discussion, it was pointed out uses of multicast is more with in enterprise. Wanted to understand how much % multicast traffic present in network
* If there is any data which can provide what % of traffic is multicast traffic. And if multicast is removed, how much unicast traffic it would add up? * Since this forum has people from deployment area, I would love to know if there is real deployment problems or its pain to deploy multicast.
These questions is to work / discussion in IETF to see what is pain points for multicast, and how can we simplify it.
Thanks Mankamana
--- Bruce Curtis bruce.curtis@ndsu.edu Certified NetAnalyst II 701-231-8527 North Dakota State University
On Thu, Aug 9, 2018 at 11:41 AM, Curtis, Bruce <bruce.curtis@ndsu.edu> wrote:
Multicast was also required for earlier versions of VXLAN. But later versions or VXLAN only require unicast.
For the far future it seems like Named Data Neworking, Content Centric Networking, Information Centric Networking, Data Centric Networking etc all list multicast as a requirement or fundamental part of their architecture.
And they would all be better served by using BIER. Greg
On Aug 8, 2018, at 4:15 PM, Greg Shepherd <gjshep@gmail.com> wrote:
Financial exchanges around the world use multicast.
On Wed, Aug 8, 2018 at 1:31 PM, Stan Barber <sob@academ.com> wrote:
As someone else remarked, part of this will depend on the type of network you are profiling. One enterprise networking may have critical internal applications that depend on multicast to work and others may have nothing but the basic requirements of the network itself (e.g. IPv6 uses multicast instead of broadcast for some network control information distribution).
On Wed, Aug 8, 2018 at 11:49 AM, Mankamana Mishra (mankamis) via NANOG < nanog@nanog.org> wrote:
Hi Every one, Recently we had good discussion over multicast uses in public internet. From discussion, it was pointed out uses of multicast is more with in enterprise. Wanted to understand how much % multicast traffic present in network
* If there is any data which can provide what % of traffic is multicast traffic. And if multicast is removed, how much unicast traffic it would add up? * Since this forum has people from deployment area, I would love to know if there is real deployment problems or its pain to deploy multicast.
These questions is to work / discussion in IETF to see what is pain points for multicast, and how can we simplify it.
Thanks Mankamana
--- Bruce Curtis bruce.curtis@ndsu.edu Certified NetAnalyst II 701-231-8527 North Dakota State University
In terms of other Internet use, the BBC recently published this white paper on the R&D efforts with HTTP Server Push/QUIC, part of which describes an "experimental IP multicast profile of HTTP over QUIC". https://www.bbc.co.uk/rd/publications/whitepaper336 Jethro. . . . . . . . . . . . . . . . . . . . . . . . . . Jethro R Binks, Network Manager, Information Services Directorate, University Of Strathclyde, Glasgow, UK The University of Strathclyde is a charitable body, registered in Scotland, number SC015263. On Thu, 9 Aug 2018, Curtis, Bruce wrote:
Multicast was also required for earlier versions of VXLAN. But later versions or VXLAN only require unicast.
For the far future it seems like Named Data Neworking, Content Centric Networking, Information Centric Networking, Data Centric Networking etc all list multicast as a requirement or fundamental part of their architecture.
On Aug 8, 2018, at 4:15 PM, Greg Shepherd <gjshep@gmail.com> wrote:
Financial exchanges around the world use multicast.
On Wed, Aug 8, 2018 at 1:31 PM, Stan Barber <sob@academ.com> wrote:
As someone else remarked, part of this will depend on the type of network you are profiling. One enterprise networking may have critical internal applications that depend on multicast to work and others may have nothing but the basic requirements of the network itself (e.g. IPv6 uses multicast instead of broadcast for some network control information distribution).
On Wed, Aug 8, 2018 at 11:49 AM, Mankamana Mishra (mankamis) via NANOG < nanog@nanog.org> wrote:
Hi Every one, Recently we had good discussion over multicast uses in public internet. From discussion, it was pointed out uses of multicast is more with in enterprise. Wanted to understand how much % multicast traffic present in network
* If there is any data which can provide what % of traffic is multicast traffic. And if multicast is removed, how much unicast traffic it would add up? * Since this forum has people from deployment area, I would love to know if there is real deployment problems or its pain to deploy multicast.
These questions is to work / discussion in IETF to see what is pain points for multicast, and how can we simplify it.
Thanks Mankamana
--- Bruce Curtis bruce.curtis@ndsu.edu Certified NetAnalyst II 701-231-8527 North Dakota State University
On 10 August 2018 at 08:44, Jethro R Binks <jethro.binks@strath.ac.uk> wrote:
In terms of other Internet use, the BBC recently published this white paper on the R&D efforts with HTTP Server Push/QUIC, part of which describes an "experimental IP multicast profile of HTTP over QUIC".
https://www.bbc.co.uk/rd/publications/whitepaper336
Jethro.
The BBC publishes this list of multicast partners but I'm not sure if it's up-to-date and they still offer multicast outside of their own network? iPlayer is unicast to consumer, so? Do they offer multicast to iPlayer to these partners or only for set-top-box services? Cheers, James.
On Fri Aug 10, 2018 at 01:02:38PM +0100, James Bensley wrote:
Do they offer multicast to iPlayer to these partners or only for set-top-box services?
Only to STB currently, with little end user device support for multicast it didn't go anywhere as a direct consumer proposition. The ISPs with enough users to make it worthwhile either had their own STB (Virgin, Sky) or jointly made one with us (Youview - BT/TalkTalk) brandon
when i was last on a proper working multicast-enabled UK university network, could pick up the BBC streams (TV and radio) using VLC :) alan
On Fri Aug 10, 2018 at 08:44:55AM +0100, Jethro R Binks wrote:
In terms of other Internet use, the BBC recently published this white paper on the R&D efforts with HTTP Server Push/QUIC, part of which describes an "experimental IP multicast profile of HTTP over QUIC".
We're doing this as part of our work on moving the entirety of broadcast, from camera to viewer, to IP. The broadcast industry is going this way now (visit IBC or NAB and see) so you'll see plenty of multicast inside their networks https://www.bbc.co.uk/rd/publications/whitepaper268 I've kept out of the multicast hate fest, it's a tool and some tools work better in some situations than others, some may be a bit old and blunt. I don't think banishing multicast is the answer. It would be better to fix the problems instead, if we don't want to sustain the content based balkanisation of the internet by content rights holders and eyeball networks that support them to exlude competition. Internet VOD is huge but there is little linear TV. VOD traffic is driving standards development not linear TV, so there is no demand to fix inter domain multicast. We think our iPlayer VOD service traffic is quite large but it is only 5% of our viewing so linear TV is not dead yet, especially for major events. We could scale our CDNs for this but multicast does it more efficiently in some networks. https://www.bbc.co.uk/rd/blog/2018-07-ultra-high-definition-uhd-viewing Our aim with MPEG-DASH is to have one standard for uni and multicast streaming where clients transparently use whichever works. If an edge network wishes to use multicast, as many do for IPTV, they can but they may have to use unicast from the origin, we didn't want to be delayed for another 10 years waiting for other networks to turn it (back) on. The edge network does not have to roll out multicast 100% as it will just be used wherever it happens to have been deployed. There have been standards for this, usually with tunnels. Using the same DASH stream format means it's simpler to do transparently this way giving networks more flexibility to handle the capacity issues when we do a World Cup in IP only. https://www.bbc.co.uk/sport/football/44850988 The latency problem remains, people don't like hearing the goal cheers through the wall and waiting for it to appear on their screen. Sometimes not all new standards, forcing video over HTTP rather than RTSP, are progress. brandon
On Wed, 8 Aug 2018 at 23:53, Stan Barber <sob@academ.com> wrote:
but the basic requirements of the network itself (e.g. IPv6 uses multicast instead of broadcast for some network control information distribution).
This is almost never true, it's rare exception rather than common case. The idea was that in IPv4 networks ARP broadcast waste bandwidth and host CPU. To fix this problem, each host (sufficiently small group of IPv6 addresses unlikely to collide) subscribes to its own multicast group. So we don't need to flood the ND traffic to hosts not needing it. But it turned out supporting ~infinitely many multicast states is harder problem than pushing frames in hardware to all ports. So all practical networks run IPv6 ND same as ARP. Another 'we fixed a problem in IPv6', which turned out to be worse than the original problem and was quietly ignored in practical networks. -- ++ytti
On 08/08/2018 11:27 PM, Saku Ytti wrote:
On Wed, 8 Aug 2018 at 23:53, Stan Barber <sob@academ.com> wrote: Another 'we fixed a problem in IPv6', which turned out to be worse than the original problem and was quietly ignored in practical networks.
Let me fix that for you. Using multicast on IPv6 grant us the ability to do more. Today, this is worthless. Will it be the same tomorrow ? Multicast without NDP is broadcast, thus for that particular thing, ipv6 is just better than ipv4.
s/NDP/MLD/ On 08/08/2018 11:36 PM, nanog@jack.fr.eu.org wrote:
On 08/08/2018 11:27 PM, Saku Ytti wrote:
On Wed, 8 Aug 2018 at 23:53, Stan Barber <sob@academ.com> wrote: Another 'we fixed a problem in IPv6', which turned out to be worse than the original problem and was quietly ignored in practical networks.
Let me fix that for you. Using multicast on IPv6 grant us the ability to do more. Today, this is worthless. Will it be the same tomorrow ?
Multicast without NDP is broadcast, thus for that particular thing, ipv6 is just better than ipv4.
On 2018-08-08 23:36, nanog@jack.fr.eu.org wrote:
Let me fix that for you. Using multicast on IPv6 grant us the ability to do more. Today, this is worthless. Will it be the same tomorrow ?
Problem is, to handle the Neigbour Discovery design (16M multicast groups), we need hardware that does not exist yet, is unlikely to exist for at least another decade and will not be down to reasonable prices (< 5 kUSD) for even longer. In the meantime, IPv6 neigbour discovery *precludes* the use of multicast for other purposes on non-small networks, because IPv6 ND will use up all multicast groups. If ND had limited itself to 256 multicast groups, it wouldn't have been a problem.
Multicast without NDP is broadcast,
(With s/NDP/MLD/ as you yourself mentioned.) That's the case for Ethernet. Hop over to the Infiniband or OmniPath world, and multicast without MLD will cause packets to be dropped. There is no such thing as broadcast on IB or OPA. (At least OmniPath does have something called "multicast LID sharing", where the IPv6 ND groups are clamped down to just 512 distinct groups, but I haven't read up on the details for how that works, yet. I don't know offhand if there is something similar for Infiniband.) /Bellman
On Wed, 8 Aug 2018, Mankamana Mishra (mankamis) via NANOG wrote:
* If there is any data which can provide what % of traffic is multicast traffic. And if multicast is removed, how much unicast traffic it would add up? * Since this forum has people from deployment area, I would love to know if there is real deployment problems or its pain to deploy multicast.
These questions is to work / discussion in IETF to see what is pain points for multicast, and how can we simplify it.
The amount of multicast traffic on an enterprise network will depend greatly on how multicast is being used, and to some extent, the type of business the enterprise is in. An enterprise that uses multicast primarily for IPTV distribution might have different business and technology drivers than, say, a hospital or healthcare organization that has patient monitors that use multicast to communicate back to a central monitoring station. The percentage of multicast traffic in those two scenarios might be vastly different, but no less important to their respective organizations. Thank you jms
Multicast is heavily used for applications such as stock trading and industrial networks. So it really depends... On Thu, Aug 9, 2018, 00:23 Justin M. Streiner <streinerj@gmail.com> wrote:
On Wed, 8 Aug 2018, Mankamana Mishra (mankamis) via NANOG wrote:
* If there is any data which can provide what % of traffic is multicast traffic. And if multicast is removed, how much unicast traffic it would add up? * Since this forum has people from deployment area, I would love to know if there is real deployment problems or its pain to deploy multicast.
These questions is to work / discussion in IETF to see what is pain points for multicast, and how can we simplify it.
The amount of multicast traffic on an enterprise network will depend greatly on how multicast is being used, and to some extent, the type of business the enterprise is in.
An enterprise that uses multicast primarily for IPTV distribution might have different business and technology drivers than, say, a hospital or healthcare organization that has patient monitors that use multicast to communicate back to a central monitoring station. The percentage of multicast traffic in those two scenarios might be vastly different, but no less important to their respective organizations.
Thank you jms
On 2018-08-08 13:49, Mankamana Mishra (mankamis) via NANOG wrote:
Hi Every one, Recently we had good discussion over multicast uses in public internet. From discussion, it was pointed out uses of multicast is more with in enterprise. Wanted to understand how much % multicast traffic present in network
* If there is any data which can provide what % of traffic is multicast traffic. And if multicast is removed, how much unicast traffic it would add up? * Since this forum has people from deployment area, I would love to know if there is real deployment problems or its pain to deploy multicast.
These questions is to work / discussion in IETF to see what is pain points for multicast, and how can we simplify it.
Thanks Mankamana
Hi Mankamana, I once worked for a financial futures broker-dealer where I implemented multicast, which was around 2009. They had one main application, which was a trading "screen" that traders and customers used to execute trades. I would guesstimate maybe 5-10% of the packets and bytes flowing over the network was multicast, depending on network conditions. In terms of bandwidth savings, I'm not sure how much we saved. We had nine or ten participants using that particular application. However, they all worked on different desks, trading different products. The app was smart enough to send only the price feeds in which the user was interested. Assuming at least 50% of the users looked at the same price feeds 50% of the time, I'd say it saved about 25-50 meg. We also had one major exchange distributing price feeds via multicast. However, that feed was not routed on our network. Our systems plugged directly into exchange-provided switches for the feed. The hurdles I had to overcome to implement multicast were: * The learning curve for PIM. Deciding on the deployment model was difficult, as were the first few support calls. We wound up going with PIM-SM w/ BSR for RP selection. * Vendor support for PIM on our gear. These were mainly troubles with PIM running on firewalls in high-availability mode. If I had to do it over again, I wouldn't have bothered with multicast. It was a great opportunity and we learned a lot, but the app had a unicast mode of operation that would have worked perfectly fine for our purposes. I work for an ISP now. We have decided not to support multicast on our network for now mainly because of the learning curve, and also because we simply don't see that much demand. Those two or three prospective customers that wanted it, wanted it for multi-site video conferencing on an MPLS VPN. Hope this helps, -Brian
On 8 August 2018 at 19:49, Mankamana Mishra (mankamis) via NANOG <nanog@nanog.org> wrote:
Hi Every one, Recently we had good discussion over multicast uses in public internet. From discussion, it was pointed out uses of multicast is more with in enterprise. Wanted to understand how much % multicast traffic present in network
* If there is any data which can provide what % of traffic is multicast traffic. And if multicast is removed, how much unicast traffic it would add up? * Since this forum has people from deployment area, I would love to know if there is real deployment problems or its pain to deploy multicast.
These questions is to work / discussion in IETF to see what is pain points for multicast, and how can we simplify it.
A recent customer uses multicast to have the same packet arrive at multiple destinations at the same time for resilience (their own internal systems, not IPTV or media etc). Having just refreshed their network for the next 5-10 years it's not going away anytime soon. Cheers, James.
On Thu, 9 Aug 2018 at 15:27, James Bensley <jwbensley@gmail.com> wrote:
A recent customer uses multicast to have the same packet arrive at multiple destinations at the same time for resilience (their own internal systems, not IPTV or media etc). Having just refreshed their network for the next 5-10 years it's not going away anytime soon.
I believe the same time delivery is motivation for stock exchanges too. One of the larger exchanges used MX and multicast, which of course does btree or utree (in this case utree) replication, which makes delivery times are very much variant. So it is very much implementation detail what type of delivery time differences to expect in different ports and it is not by design superior to unicast. -- ++ytti
On 9 August 2018 at 13:57, Saku Ytti <saku@ytti.fi> wrote:
On Thu, 9 Aug 2018 at 15:27, James Bensley <jwbensley@gmail.com> wrote:
A recent customer uses multicast to have the same packet arrive at multiple destinations at the same time for resilience (their own internal systems, not IPTV or media etc). Having just refreshed their network for the next 5-10 years it's not going away anytime soon.
I believe the same time delivery is motivation for stock exchanges too. One of the larger exchanges used MX and multicast, which of course does btree or utree (in this case utree) replication, which makes delivery times are very much variant. So it is very much implementation detail what type of delivery time differences to expect in different ports and it is not by design superior to unicast.
I'm definately not saying it was a good idea / good design :) I'm just saying that it's another example of multicast in use that is not the usual IPTV or financial trading (aeronautical in this case). Cheers, James.
participants (14)
-
Alan Buxey -
Arie Vayner -
Brandon Butterworth -
Brian Knight -
Curtis, Bruce -
Greg Shepherd -
James Bensley -
Jethro R Binks -
Justin M. Streiner -
Mankamana Mishra (mankamis) -
nanog＠jack.fr.eu.org -
Saku Ytti -
Stan Barber -
Thomas Bellman