Multiplex communications – Data flow congestion prevention or control – Flow control of data transmission through a network
Reexamination Certificate
1999-10-15
2004-08-31
Hsu, Alpus H. (Department: 2665)
Multiplex communications
Data flow congestion prevention or control
Flow control of data transmission through a network
C370S395520, C370S414000, C709S232000, C709S238000
Reexamination Certificate
active
06785238
ABSTRACT:
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a LAN relaying/switching apparatus, and in particular to a LAN relaying/switching apparatus which accommodates many LAN transmission lines.
In recent years, LAN transmission lines have been made to have a high-speed and large capacity so that it has been required in the LAN relaying/switching apparatus where many LAN transmission lines are concentrated to suppress the spread of faults having occurred in a part of the transmission lines to the other normal transmission lines.
2. Description of the Related Art
FIG. 10
shows an arrangement of a conventional LAN relaying/switching apparatus. This relaying/switching apparatus is composed of terminal portions
20
on the input side and the output side of the apparatus which terminate transmission lines, a switch portion
14
which exchanges data from the terminal portions
20
on the input side and provides the same to the terminal portions
20
on the output side, and queue portions
60
a
-
60
c
and
60
d
-
60
f
respectively arranged on the input side and the output side of the switch portion
14
for establishing data forwarding paths.
In this arrangement, the terminal portions
20
on the input side are composed of two terminal portions based on the IEEE802.3 and a single ATM terminal portion so that the terminal portions of different interfaces exist together.
In such a conventional LAN relaying/switching apparatus having physical interface terminal portions based on the IEEE802.3, a jam state {circle around (
1
)}, caused in the transmission line on the output side for instance, causes an overflow state {circle around (
2
)} in the output queue portion
60
d
placed in front of the terminal portions
20
which terminate the transmission line. The overflow state {circle around (
2
)} causes an overflow state {circle around (
3
)}in the queue portions
60
a
-
60
c
on the input side which transmit the data to the queue portion
60
d.
Being based on the IEEE802.3 in this case, the terminal portions
20
detect the overflow state {circle around (
3
)} of the queue portions
60
a
and
60
b
on the input side, perform a flow control {circle around (
4
)} a regulated by the IEEE802.3x and the IEEE802.3z, and suppress the data causing the overflow state {circle around (
3
)}.
On the other hand, the overflow state {circle around (
3
)} of the queue portion
60
c
on the input side has no flow control corresponding to the IEEE802.3x and the IEEE802.3z since the terminal portion
20
on the input side is the ATM terminal portion. Therefore, it is impossible to selectively suppress the transmission of the data from the apparatus transmitting the data causing the overflow state {circle around (
3
)}. For this reason, there has been a problem that cells which have overflowed in the queue portion
60
c
on the input side are to be discarded as shown by {circle around (
5
)}.
SUMMARY OF THE INVENTION
It is accordingly an object of the present invention to provide a LAN relaying/switching apparatus which accommodates many transmission lines and suppresses the spread of jams caused in a part of the transmission lines to the other normal transmission lines.
In order to achieve the above-mentioned object, a LAN relaying/switching apparatus, according to claim
1
, of the present invention comprises; a plurality of terminal portions for inputting data from an external apparatus, a queue portion for performing an input/output management for a switch portion of the data, and a controller for performing a flow control which limits a data transmission for the terminal portions which have inputted the data when a threshold value preset to an output queue of the queue portion is exceeded.
Namely, the data from an external apparatus is inputted to the queue portion through the terminal portions is queued until a path is set up at the switch portion, and is then transferred to the queue portion on the output side through the setup path. In the presence of a jam in the transmission line on the output side, the data is queued at the queue portion on the output side. When the queue (queued number) exceeds the preset threshold value, the controller performs the flow control for limiting the data transfer to the terminal portion which has inputted the data which has exceeded the threshold value.
This operation enables the transmission of the data causing a jam to be limited and prevents the data from overflowing and being lost at the queue portion.
Also, in the present invention according to claim
2
, the controller may identify a real terminal portion based on an MAC address included in the data which has exceeded the threshold value.
Namely, the controller identifies the terminal portion from which the data is transmitted based on the MAC address included in the data which has exceeded the threshold value and limits the data transfer to the identified terminal portion.
Also, in the present invention according to claim
3
, the controller may identify a real terminal portion based on an IP address included in the data which has exceeded the threshold value.
Furthermore, in the present invention according to claim
4
, the controller may identify a real terminal portion based on protocol type information included in the data which has exceeded the threshold value.
Also, a LAN relaying/switching apparatus, according to claim
5
, of the present invention may comprise; a plurality of terminal portions for inputting data from an external apparatus, a queue portion for performing an input/output management for a switch portion of the data, and a controller for performing a flow control which limits a specific data flow from the terminal portions where an output queue of the queue portion has exceeded a preset threshold value.
Namely, in the same way as the invention of claim
1
, when the queue of the output queue portion has exceeded the threshold value the controller performs the flow control to the data. However, different from the invention of claim
1
, this flow control is performed to a specific data flow at the time when the threshold value has been exceeded.
This enables the transmission of the specific data flow causing a jam to be limited and prevents the data from overflowing and being lost at the queue portion on the output side.
Also, in the present invention according to claim
6
, the controller may identify the specific data flow based on an MAC address.
Also, in the present invention according to claim
7
, the controller may identify the specific data flow based on an IP address.
Also, in the present invention according to claim
8
, the controller may identify the specific data flow based on protocol type information.
Also, in the present invention according to claim
9
, the controller may identify the specific data flow based on a TCP or UDP port number.
Also, in the present invention according to claim
10
, the controller may identify the specific data flow based on a flow label in IPv6.
Moreover, in the present invention according to claim
11
, the controller may identify the specific data flow based on one of VPI and VCI information in ATM.
Namely, in the present invention according to any one of claims
6
-
11
, the controller may identify the specific data flow whose transmission is limited based on one of the MAC address, the IP address, the protocol type information, the port number, the flow label, as well as the VPI and VCI information included in the data flow at the time when the threshold value is exceeded.
Also, in the present invention according to claim
12
, when any one of a plurality of threshold values which are preset is exceeded, the controller may perform the flow control which limits the specific data flow.
Namely, in the invention of claim
1
, a single threshold value is set in the output queue portion, while in the present invention a plurality of threshold values are set. Thus, when the data flow exceeds one of the threshold values, the controller can perform a more minute flow control by limiting a specific data flow stepw
Fujitsu Limited
Hsu Alpus H.
Katten Muchin Zavis & Rosenman
LandOfFree
LAN relaying/switching apparatus does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with LAN relaying/switching apparatus, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and LAN relaying/switching apparatus will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-3350942