EP0902569A1
Expired / Lapsed
EP
⏱️ 0.0 years remaining
Method and system for a unicast endpoint client to access a multicast internet protocol (ip) session
Assignee: AT&T Inc
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Filing: 1998-09-01
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Granted: —
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Expires: 2018-09-01
Abstract
Abstract Unicast endpoint clients (110, 111, 115) on an IP Unicast network (107, 108) are provided access to Multicast sessions on an IP Multicast network (101) through a Multicast-Unicast gateway server (120, 121). The server obtains information about sessions on the Multicast network and makes such information available to a Unicast client on the Unicast network upon request by the client. Upon being presented with a list describing the subject matter of each session, the user at the Unicast client selects the session to which he or she wants to join, which causes the Multicast-Unicast server to join the appropriate session on behalf of the requesting client for each media type in which the joining client wants to be a participant. The server then sets a bi-directional Unicast User Datagram Protocol (UDP) stream between itself and the client. All packets then received by the server from the Unicast client are address-translated to the appropriate Multicast session address. In addition, all packets received by the server on the Multicast session address are address-translated and sent to the Unicast client. The Unicast client is then able to participate in the Multicast session as both a sender and a receiver of packets to and from other Unicast and Multicast clients which are active during the session. Further, the Unicast client is capable of creating a new session, recording a session in the network for later retrieval and playback, and creating and accessing low bandwidth versions of existing sessions.
Inventors
- 👤 David Hilton Shur
- 👤 Alexandr Zelezniak
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-10-24 13:25
CPC Classifications
H; H04; H04L; H04L65/00; H04L65/1066; H04L65/1069; H04L12/00; H04L12/02; H04L12/16; H04L12/18; H04L12/185; H04L12/1836; H04M; H04M3/00; H04M3/42; H04M3/56; H04M3/567
Claims Analysis
Total Claims: 32
Claim 1
Independent Claim
161 words
A method of providing access to a Multicast session on a
Multicast network to a Unicast client on a Unicast network comprising: accumulating at a gateway server interconnecting the Multicast
network and the Unicast network directory information relating to Multicast
sessions on the Multicast network; supplying the Unicast client with the directory information
accumulated by the gateway server; receiving at the gateway server from the Unicast client a request to
join a selected session chosen from the directory information; joining the requested-for Multicast session at the gateway server on
behalf of the Unicast client; converting at the gateway server an address of Multicast packets
received on a Multicast address associated with the requested-for session
to a Unicast address of the Unicast client and sending the Multicast packets
received by the gateway server on the Multicast address to the Unicast
client; and transmitting packets received at the gateway server from the Unicast
client to the Multicast address associated with the requested-for session.
Claim 2
Dependent Claim
43 words
The method of claim 1 wherein the request to join a Multicast
session is a request to join at least one group of a plurality of groups
associated with the Multicast session, each of said plurality of groups having
an associated Multicast address.
Claim 3
Dependent Claim
20 words
The method of claim 2 wherein each of said at least one group is
associated with a different media type.
Claim 4
Dependent Claim
20 words
The method of claim 1 further comprising before supplying the
Unicast client with the directory information, authenticating the Unicast
client.
Claim 5
Dependent Claim
24 words
The method of claim 4 wherein the authenticating comprises
receiving at the gateway server a login identity and a password from the
Unicast client.
Claim 6
Dependent Claim
21 words
The method of claim 1 wherein the Unicast and Multicast networks
are IP (Internet Protocol) Unicast and IP Multicast networks, respectively.
Claim 7
Dependent Claim
22 words
The method of claim 6 wherein packets are transmitted between
the gateway server and the Unicast client using the User Datagram
Protocol.
Claim 8
Dependent Claim
32 words
The method of claim 6 wherein the directory information
comprises an HTML page having a plurality of URLs each pointing to
information associated with a Multicast session on the IP Multicast network.
Claim 9
Dependent Claim
13 words
The method of claim 6 wherein the IP Multicast network is the
MBONE.
Claim 10
Independent Claim
105 words
A method of creating a Multicast session on a Multicast network
by a Unicast client on a Unicast network comprising: accumulating at a gateway server interconnecting the Multicast
network and the Unicast network directory information relating to Multicast
sessions on the Multicast network; supplying the Unicast client with the directory information
accumulated by the gateway server; receiving a request at the gateway server from the Unicast client to
create a Multicast session; receiving and storing at the gateway server information about the
Multicast session; and announcing the Multicast session by the gateway server onto the
Multicast network onto a predetermined Multicast address for such
announcements.
Claim 11
Dependent Claim
21 words
The method of claim 10 wherein the Unicast and Multicast
networks are IP (Internet Protocol) Unicast and IP Multicast networks,
respectively.
Claim 12
Dependent Claim
15 words
The method of claim 10 wherein the session is announced
periodically onto the Multicast network.
Claim 13
Independent Claim
19 words
The method of 10 further comprising before supplying the
Unicast client with the directory information, authenticating the Unicast
client.
Claim 14
Dependent Claim
31 words
The method of claim 13 further comprising after receiving a
request at the gateway server from the Unicast client to create a session,
authenticating the Unicast client to create a session.
Claim 15
Independent Claim
107 words
A method of recording a Multicast session on a Multicast network
by a Unicast client on a Unicast network comprising: accumulating at a gateway server interconnecting the Multicast
network and the Unicast network directory information relating to Multicast
sessions on the Multicast network; supplying the Unicast client with the directory information
accumulated by the gateway server; receiving a request at the gateway server from the Unicast client to
record a selected Multicast session chosen from the directory information;
and sending a message containing information about the selected
Multicast session from the gateway server to a recording server connected
to the Multicast network to record the selected session.
Claim 16
Dependent Claim
23 words
The method of claim 15 wherein the Unicast network and the
Multicast network are IP (Internet Protocol) Unicast and IP Multicast
networks, respectively.
Claim 17
Dependent Claim
29 words
The method of claim 15 further comprising receiving at the
gateway server from the Unicast client information about the selected
Multicast session including when to start and stop recording.
Claim 18
Dependent Claim
31 words
The method of claim 17 wherein the information received at the
gateway server from the Unicast client further includes an identification of
specific media to record of the selected Multicast session.
Claim 19
Dependent Claim
20 words
The method of claim 15 further comprising before supplying the
Unicast client with the directory information, authenticating the Unicast
client.
Claim 20
Dependent Claim
31 words
The method of claim 19 further comprising after receiving a
request at the gateway server from the Unicast client to record a session,
authenticating the Unicast client to record a session.
Claim 21
Dependent Claim
64 words
The method of claim 15 further comprising: receiving a request at the gateway server from the Unicast client to
access the recorded session; sending a message to the recording server from the gateway server
to the recording server to retrieve the recorded session; receiving the recorded session at the gateway server; and sending the recorded session from the gateway server to the Unicast
client.
Claim 22
Independent Claim
304 words
A method of providing access to a Multicast session on a
Multicast network to a Unicast client on a Unicast network comprising: accumulating at a gateway server interconnecting the Multicast
network and the Unicast network directory information relating to Multicast
sessions on the Multicast network, the directory information including for
each session a Multicast address for the session and a required bandwidth
of the session; supplying the Unicast client with the directory information
accumulated by the gateway server; receiving at the gateway server from the Unicast client a request to
join a selected session chosen from the directory information; determining an estimate of the available bandwidth between the
gateway server and the Unicast client; if the estimate of the available bandwidth is less than the required
bandwidth for the selected session, selecting a coding rate lower than a
coding rate associated with the selected session; sending a message from the gateway server to a transcoding server
connected to the Multicast network to rate-adapt the coding rate associated
with the selected session to the selected lower coding rate; receiving at the gateway server from the transcoding server an
indication of the Multicast address to which the rate-adapted selected
session is being transmitted; joining the rate-adapted session on behalf of the Unicast client at the
gateway server on the indicated Multicast address to which the rate-adapted
selected session is being transmitted; converting at the gateway server the address of the Multicast packets
received on the Multicast address to which the rate-adapted selected
session is being transmitted to a Unicast address of the Unicast client and
sending the Multicast packets received by the gateway server on that
Multicast address to the Unicast client; and transmitting packets received at the gateway server from the Unicast
client to the Multicast address to which the rate-adapted selected session is
transmitted.
Claim 23
Dependent Claim
22 words
The method of claim 22 wherein the Unicast and Multicast
networks are IP (Internet Protocol) Unicast networks and IP Multicast
networks, respectively.
Claim 24
Dependent Claim
43 words
The method of claim 22 wherein the request to join a Multicast
session is a request to join at least one group of a plurality of groups
associated with the Multicast session, each of said plurality of groups having
an associated Multicast address.
Claim 25
Dependent Claim
19 words
The method of claim 24 wherein each of said plurality of groups
is associated with a different media type.
Claim 26
Dependent Claim
50 words
The method of claim 22 wherein determining an estimate of the
available bandwidth comprises: transmitting a series of test packets to the Unicast client; receiving an echo of these test-packets back from the Unicast client; and comparing the transmitted series of test-packets with the received
echo of these test packets.
Claim 27
Dependent Claim
127 words
A Multicast-Unicast server comprising: means for accumulating from a connected-to Multicast network
directory information relating to Multicast sessions on the Multicast network; means for receiving from a Unicast client on a Unicast network
connected to the server a request to join a Multicast session from among
the sessions accumulated in the directory information; means for joining the requested-for Multicast session on behalf of the
client; and means for converting the Multicast address of the Multicast packets
on the requested-for Multicast session to a Unicast address associated with
the Unicast client and for sending the Multicast packets on the requested-for
Multicast session to the Unicast client at that Unicast address, and for
sending packets received from the Unicast client to the Multicast address
associated with the selected session.
Claim 28
Dependent Claim
31 words
The server of claim 27 wherein the Multicast network and the
Unicast network the server is connected to are an IP (Internet Protocol)
Multicast network and an IP Unicast network, respectively.
Claim 29
Dependent Claim
21 words
The server of claim 28 wherein packets are transmitted between
the server and the Unicast client using the User Datagram Protocol.
Claim 30
Dependent Claim
42 words
The server of claim 27 wherein the request to join a Multicast
session is a request to join at least one group of a plurality of groups
associated with the Multicast session, each of plurality of groups having an
associated Multicast address.
Claim 31
Dependent Claim
19 words
The server of claim 30 wherein each of said plurality of groups is
associated with a different media type.
Claim 32
Dependent Claim
37 words
The server of claim 27 wherein the means for converting also
sends packets received from the Unicast client to another Unicast client
associated with the server and which said another client is also connected
to the session.
References Cited (Backward Citations)
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