How to connect to the MBone
The Multicast Internet (commonly known as "the MBone")
is the region of the public Internet that's connected by
- Am I already on the MBone?
- OK, I know that I'm not already on the MBone. What do I do now?
- I asked my ISP about connecting to the MBone, but they want more information about how to do this. What can I tell them?
- My ISP is on the MBone, but the router/portmaster that they use to give me access does not support multicast. What can we do?
- I've asked my ISP, but they don't want to connect to the MBone. Is there anything else I can do?
- My network uses a firewall. Can I access the MBone?
- I'm an ISP that offers MBone access to my customers. How can I promote my services?
- More information about the MBone...
Am I already on the MBone?
One way to find out for sure is to download and run a
SDP/SAP browser, such as
(In "multikit", open the "SDP default directory".)
These programs listen on the MBone for periodic announcements
of multicast sessions.
If you don't see any announcements within a minute or so,
you're probably not on the MBone.
OK, I know that I'm not already on the MBone. What do I do now?
Your computer is probably already capable of sending and receiving IP multicast
(Note, in particular, that Windows 95 (and later) supports IP multicast.)
However, the router or 'portmaster' that connects you to your ISP might not support
Also, your ISP itself might not yet be on the MBone.
The first thing to do is to ask your ISP if they will (i) connect to the MBone, and
(ii) reconfigure their routers/portmasters - if necessary - so that you
and other customers
can get MBone access.
(Also, be sure that your ISP gives you access to the public MBone, and not just to some private multicast network.)
I asked my ISP about connecting to the MBone, but they want more information about how to do this. What can I tell them?
Your ISP can probably get some advice from their router vendor.
(Cisco customers can also find information online
Your ISP should also contact its upstream provider(s).
(If it has Sprint as an upstream provider, it might try sending a query to
If it has UUNet (alter.net) as an upstream provider, it could try "firstname.lastname@example.org",
and ask for UUNet's "MBone Gold" program.
Another multicast contact at UUNet is Kevin Gatesman: "email@example.com")
Finally, your ISP could try sending a query to the general
"MBone engineering" mailing list: "firstname.lastname@example.org".
(To subscribe to this mailing list, contact
If your ISP is looking for more basic information about IP multicast (e.g.,
"what is it"; "what are its benefits"), then you could refer them to
My ISP is on the MBone, but the router/portmaster that they use to give me access does not support multicast. What can we do?
First, they should make sure that the router/portmaster really can't support multicast routing.
It may be possible to do so simply by reconfiguring it.
If your ISP really can't set up native multicast routing to you, then there are a couple of alternatives:
- (The best choice) If you have a Unix machine at your site,
you can set up DVMRP multicast routing, using the
multicast routing agent.
Your ISP will need to configure their end of the DVMRP tunnel,
either from one of their routers, or by running "mrouted" themselves.
- Alternatively, you can set up UDP-level multicast tunneling between
you and your ISP.
Your ISP can run a
server such as
At your end, you will need to run a UMTP client,
such as the
I've asked my ISP, but they don't want to connect to the MBone. Is there anything else I can do?
Yes, you can switch to another ISP.
If your current ISP is not giving you the service you desire,
then you should consider another.
"Multicast Technologies" has compiled a partial list of
ISPs that support
However, if you don't want to switch ISPs, then you
can try asking your ISP's upstream providers if they can give you an
(using either "mrouted" or "liveGate").
Alternatively, if you know someone - located topologically nearby on the Internet - who's
already on the MBone,
then they might be willing to give you a tunnel.
(If you're in Europe, you may find
You might aso try asking the "email@example.com" mailing list (see above).
My network uses a firewall. Can I access the MBone?
Yes - if your firewall's administrator lets you.
I.e., if your administrator permits certain specific multicast groups
to be carried across your firewall, then he can set up
to relay these groups.
(For a more detailed discussion of the issues involved with
relaying multicast traffic across a firewall,
see this RFC.)
I'm an ISP that offers MBone access to my customers. How can I promote my
You can get yourself added to Stardust Forums'
ISPs that support
Please contact Jason Utz: "firstname.lastname@example.org".
More information about the MBone...
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