JP4036591B2 - Communication device and network - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a network, and can be applied to, for example, MAC (Media Access Control) control in a computer network such as a LAN (Local Area Network).
[0002]
The present invention also relates to a communication device as a component of such a network, and is suitable for application to, for example, an Internet telephone.
[0003]
[Prior art]
A regular telephone is connected to the exchange, whereas an Internet telephone is connected to a computer network. For this reason, Internet telephones are usually equipped with a LAN connector for connecting to a computer network.
[0004]
On the other hand, in today's widespread use of computers, personal computers are common sense, especially in business environments. However, with current devices, there is a tendency for network equipment to increase because separate LAN cables must be wired for Internet telephones and computers.
[0005]
In order to cope with such a tendency, it is effective to accommodate the telephone 1 and the personal computer 15 in one LAN cable 11 as shown in FIG.
[0006]
That is, the telephone 1 connected to the network 10 with one LAN cable 11 further takes a connection form in which the personal computer 15 is further connected with the LAN cable 17.
[0007]
[Problems to be Solved by the Invention]
However, when this connection form is adopted, since the Internet telephone 1 having many restrictions in terms of hardware and software must process not only its own communication but also the communication of the personal computer 15, there are some cases. A problem occurs.
[0008]
One of them is a voice packet that the Internet telephone 1 itself transmits to the computer network 10 when the amount of computer communication packets that the personal computer 15 transmits to the computer network 10 (the concentrator (switching HUB) 16 thereof) is large. The transmission of can be interrupted.
[0009]
Due to this interruption, the other party (for example, the user of the telephone 4 in the figure) who is in a call with the Internet telephone 1 will hear the interrupted voice and cannot continue a comfortable call.
[0010]
In order to solve this problem, the MAC (Media Access Controller) in the telephone 1 always sends voice packets to the computer network 10 in preference to computer communication packets, thereby eliminating voice interruptions. It is also possible.
[0011]
However, in this case, the telephone set 1 having the internal configuration shown in FIG. 2 always sends a packet input to the telephone set 1 from the personal computer 15 side only to the switching HUB 16 side. Cannot receive the packet from the side.
[0012]
That is, the telephone 1 merely mediates the exchange of packets between the computer 15 and the switching HUB 16 through the route TR2, and the packet input from the computer 15 to the telephone 1 is addressed to the telephone 1. However, the telephone set 1 could not directly receive the packet.
[0013]
As described above, the telephone 1 and the computer 15 need to communicate with each other in an application in which the telephone 1 and the personal computer 15 are linked.
[0014]
For example, an application for making a dial call from the personal computer 15 to the telephone 1, an application for pop-up displaying on the personal computer 15 that the telephone 1 has been received, an application for making detailed settings of the telephone 1 from the personal computer 15, etc. This is the case.
[0015]
When using such an application, the transmission path of the packet transmitted from the computer 15 to the telephone 1 is as follows: computer 15 → cable 17 → phone 1 → LAN cable 11 → switching HUB 16 → LAN cable 11 → phone 1 It becomes redundant.
[0016]
However, this enables the switching HUB 16 to recognize that a plurality of communication devices (in this case, the Internet telephone 31 and the personal computer 15) are connected to the same port, and to enable communication between the plurality of communication devices. This is a case where a function is provided, and a general switching HUB is usually not equipped with such a function.
[0017]
If the switching HUB 16 is equipped with such a function, demonstrating such a function itself places a heavy load on the switching HUB 16, and the internal state of the switching HUB 16 (packet congestion level, etc.) ) Increases the possibility of packet loss, which is disadvantageous in terms of communication quality and communication efficiency.
[0018]
In order to avoid this problem, for example, the internal configuration of the telephone 1 is modified as shown in FIGS. 2 to 4, and the personal computer 15, the telephone 1 itself, and the switching HUB 16 (HUB port) are incorporated in the telephone 1. (HUB, switching HUB) may be used for connection.
[0019]
However, if a single telephone has a built-in HUB or switching HUB, the price of the telephone 1 becomes very expensive, which is not practical.
[0020]
On the other hand, it is also possible to cause the CPU 22 of the telephone 1 to interpret the destination of the packet transmitted from the computer 15 and passing through the telephone 1, and handle the packet addressed to the own telephone 1 differently from the other packets.
[0021]
However, this places an excessive load on the CPU 22, and the processing capacity originally used for the communication of the telephone 1 itself is consumed, increasing the possibility that the communication of the telephone 1 will be hindered.
[0022]
[Means for Solving the Problems]
In order to solve this problem, in the first invention, a first interface means for connecting to a network, a second interface means for transmitting and receiving voice packets, and a third interface means for computer data communication, A communication apparatus comprising a central processing unit connected to the second interface means; (1) a first medium access control unit for connecting the first interface means and the second interface means; 2) a second medium access control unit for connecting the third interface unit and the second interface unit, (3) the inside of the second medium access control unit, and the first medium access control unit By connecting the inside, the second interface means is interposed between the first interface means and the third interface means. Characterized in that also includes a bypass means for connecting a short path.
[0023]
In the second invention, in order to connect to the network, the first interface means capable of communicating in the first communication mode including the condition relating to the data transfer capacity, the second interface means for voice packet transmission / reception, and the computer For data communication, the data is transmitted between the third interface means that communicates in the second communication mode having at least a data transfer capacity smaller than that in the first communication mode, and between the first interface means and the third interface means. In the communication apparatus that can mediate computer data communication performed by using the first interface means and the third interface means, and the third interface means. Between the computer terminal connected to the network and the network When the signal is performed, characterized by comprising a communication mode changing means for changing the first communication mode so as to correspond to the second communication mode.
[0024]
Further, in the network according to the third invention, (1) the communication device according to any one of claims 1 to 3, (2) a line concentrator connected to the first interface means of the communication device, and (3) And a communication computer terminal connected to the third interface means of the communication device.
[0025]
DETAILED DESCRIPTION OF THE INVENTION
(A) Embodiment
The first and second embodiments will be described below by taking as an example the case where the communication apparatus and network of the present invention are applied to an Internet telephone and a LAN including the Internet telephone.
[0026]
In the present embodiment, a MAC capable of switching between a route in which transmission / reception circuits of two built-in MACs (media access controllers) bypass each other and a route in which only a packet specifying its own address as a transmission destination is transmitted to the CPU side can be switched. A device is provided.
[0027]
(A-1) Configuration of the first embodiment
The configuration of the LAN 30 of the present embodiment is the same as that of the computer network 10 shown in FIG. Therefore, FIG. 3 is also an explanatory diagram of this embodiment as it is.
[0028]
That is, as shown in FIG. 3, the LAN 30 of the present embodiment includes telephones 31 and 2 to 4, LAN cables 11 to 14 and 17, a personal computer 15, and a switching HUB 16.
[0029]
Of these, the Internet telephone 31 has an internal configuration shown in FIG. 5, unlike FIGS. 2 and 4.
[0030]
(A-1-1) Internal configuration of Internet telephone
In FIG. 5, an Internet telephone 31 includes a codec (CODEC) 20, a memory 21, a CPU 22, PHYs (Physical Layer Protocol) units 24 and 25, a MAC device 32, and a HUB port 50. And a personal computer port 51.
[0031]
Among these, the functions of the constituent elements 20, 21, 22, 24, 25 themselves denoted by the same reference numerals as those in FIG.
[0032]
Therefore, the difference between the Internet telephone 31 of the present embodiment and the conventional telephone 1 is mainly limited to the portion related to the MAC device 32.
[0033]
The MAC device 32 is in charge of processing in the media layer of each communication process, and transmits and receives packets between the bus BA1, PHY 24 for switching HUB connection, and PHY 25 for personal computer 15 connection.
[0034]
That is, the MAC device 32 mediates packet exchange between the personal computer 15 and the switching HUB 16, and receives and switches the voice packet obtained by the codec 20 encoding the voice signal input from the microphone 20A. A function for performing mediation processing of packets transmitted to the HUB 16 or bidirectionally exchanged between the CPU 22 and the personal computer 15 is provided.
[0035]
The internal configuration of the MAC device 32 is shown in FIG.
[0036]
(A-1-2) Internal configuration of MAC device 32
In FIG. 1, the MAC device 32 includes two elements MAC 33 and 34, a FIFO (first-in first-out type memory) 35, and a bus interface 36.
[0037]
Of these, the bus interface 36 is an interface to the bus BA1 connected to the codec 20, the CPU 22, and the like.
[0038]
The element MAC 33 includes a FIFO 40A, a priority control circuit 41A, and a transmission / reception circuit 42A.
[0039]
The FIFO 40A is a buffer for exchanging packets with the bus interface 36, receiving packets from the transmission / reception circuit 42A, and sending the packets to the priority control circuit 41A.
[0040]
When the packet (voice packet) sent from the FIFO 40A and the packet transmission request sent from the FIFO 35 compete with each other, the priority control circuit 41A gives priority to the voice packet sent from the FIFO 40A to the transmission request. It is a control circuit that gives permission. By the function of the priority control circuit 41A, voice packets are preferentially sent out from the transmission / reception circuit 42A, and the other party who is talking to the Internet telephone 31 can make a comfortable call without interruption of the voice.
[0041]
The other element MAC 34 has the same configuration as the element MAC 33 and includes a FIFO 40B, a priority control circuit 41B, and a transmission / reception circuit 42B. The FIFO 40B corresponds to the FIFO 40A, the priority control circuit 41B corresponds to the priority control circuit 41A, and the transmission / reception circuit 42B corresponds to the transmission / reception circuit 42A.
[0042]
However, the technical meaning of the priority control circuit 41B is usually different from that of the priority control circuit 41A. Except for the case where the Internet telephone 31 and the personal computer 15 make a call using telephone software, the required level of real-time property in data communication between the personal computer 15 and the Internet telephone 31 is not high, and this is not given priority. This is because it is unlikely that a noticeable inconvenience that the user will experience, such as the interruption of the voice described above, will occur.
[0043]
Therefore, whether the priority control of the priority control circuit 41B prioritizes the packet transmission request sent from the FIFO 2 or the packet transmission request sent from the FIFO 35 depends on the application linked with the personal computer 15. May be changed depending on whether the degree of real-time communication required is high or low.
[0044]
However, in this embodiment, the transmission request issued from the FIFO 40B is sent out from the FIFO 35 in order to give priority to the communication between the Internet telephone 31 and the personal computer 15 over the communication between the third party and the personal computer 15. It shall be granted with priority over the transmitted request.
[0045]
Basically, the element MAC 33 is a circuit that connects the switching HUB 16 connected via the PHY 24 and the bus interface 36, and the element MAC 34 includes the personal computer 15 connected via the PHY 25, and the bus interface. 36, but also supports other connection relationships via the FIFO 35.
[0046]
That is, packet communication between the personal computer 15 and the switching HUB 16 is also supported by the element MACs 33 and 34 via the FIFO 35.
[0047]
The FIFO 35, which is a buffer memory effective for bypassing the transmission path between the personal computer 15 and the switching HUB 16, does not perform packet filtering as in the FIFO 40A or the like, accumulates all packets, and gives priority control circuit 41B (or 41A). ) To obtain a permission from the priority control circuit 41B (or 41A), and send a packet to each of the transmission / reception circuits 42A and 42B.
[0048]
The transmission / reception circuit 42B in the element MAC 34 interprets the destination address of the packet supplied from the personal computer 15 to the telephone 31 and activates the accept signal only for the packet determined to be addressed to the Internet telephone 31. Thus, writing to the FIFO 40B is permitted. That is, the transmission / reception circuit 42B executes filtering (reception filtering function) so that only packets addressed to the Internet telephone 31 are supplied from the FIFO 40B to the bus interface 36.
[0049]
The transmission / reception circuit 42A in the element MAC 33 also performs similar filtering so that only packets addressed to the Internet telephone 31 are supplied from the FIFO 40A to the bus interface 36.
[0050]
With these filtering and bypass FIFOs 35, the CPU 22 only has to process packets whose destination (address) or source (address) is its own Internet telephone 31, and its processing capability is directly related to itself. Can only be used for communication.
[0051]
The operation of the present embodiment having the above configuration will be described below.
[0052]
(A-2) Operation of the first embodiment
Of the packets communicated in the LAN 30, all the packets related to the Internet telephone 31 can be classified into six types shown in FIG. 6 from the viewpoint of the transmission destination address D and the transmission source address G.
[0053]
In FIG. 6, S is an address that designates the switching HUB 16 side, for example, the telephone 4 as viewed from the Internet telephone 31, I is an address that designates the Internet telephone 31 itself, and P is an address that designates the personal computer 15. It is.
[0054]
In FIG. 6, a packet P1 (S, I) indicates a packet that is transmitted to the switching HUB 16 side by the Internet telephone 31 when the transmission destination is S and the transmission source is I.
[0055]
Similarly, P2 (P, I) indicates a packet whose destination is P and the source is I, P3 (I, S) indicates a packet whose destination is I and the source is S, and P4 (P, S ) Indicates a packet whose destination is P and whose source is S, P5 (I, P) indicates a packet whose destination is I and whose source is P, and P6 (S, P) is a destination where the destination is S Indicates a packet whose origin is P.
[0056]
Note that the contents of the data portion DT of each packet P1 to P6 may be user data for communication purposes or control data for controlling the communication.
[0057]
When the CPU 22 of the Internet telephone 31 intends to transmit a packet, the transmission packet is written in the bus interface 36. At this time, the transmission packet is either P1 or P2.
[0058]
In response to this, the bus interface circuit 36 writes the data in both the FIFOs 40A and 40B.
[0059]
The FIFOs 40A and 40B make transmission requests to the priority control circuits 42A and 42B in each element MAC 33 or 34, and after obtaining permission from the priority control circuits 41A and 41B, start sending transmission packets.
[0060]
When the transmission / reception circuits 42A and 42B can exert the same filtering function (transmission filtering function) as the above-described reception filtering function on the packet received from the outside also on the transmission packet transmitted from the inside to the outside, the transmission packet is P1. If (S, I), the packet may be transmitted only from the transmission / reception circuit 42A, and the transmission / reception circuit 42B may not transmit the packet.
[0061]
However, in this embodiment, in order to save hardware and software of the Internet telephone 31, such a transmission filtering function is not implemented.
[0062]
Therefore, in the present embodiment, the transmission packet P1 (S, I) is transmitted not only from the originally required transmission / reception circuit 42A but also from the transmission / reception circuit 42B, and the personal computer 15 filters the packet.
[0063]
The processing in the Internet telephone 31 is the same when the transmission packet is P2 (P, I). The personal computer 15 that should receive this packet P2 (P, I) receives the packet P2, and the switching HUB 16 that should not receive it performs filtering.
[0064]
Next, the case where the Internet telephone 31 receives a packet will be described. The packet received by the Internet telephone 31 is any one of P3 to P6 in FIG.
[0065]
Of P3 to P6, the packet received by the transmission / reception circuit 42A connected to the HUB port 50 is P3 or P4.
[0066]
Regardless of which packet P3 or P4 is received, the transmission / reception circuit 42A supplies the received packet to both the FIFO 40A and the bypass FIFO 35.
[0067]
In the FIFO 40A, when the received packet is P3 (I, S), the transmission / reception circuit 42A does not perform reception filtering with the accept signal active, so the received packet P3 is supplied from the FIFO 40A to the bus interface 36.
[0068]
The received packet P3 written to the FIFO 35 reaches the personal computer 15 and is then filtered and discarded by the personal computer 15.
[0069]
On the other hand, when the received packet is P4 (P, S), the transmission / reception circuit 42A performs reception filtering with the accept signal in an inactive state and discards the received signal, so that the received packet P4 is supplied from the FIFO 40A to the bus interface 36. There is nothing.
[0070]
The received packet P4 written in the FIFO 35 reaches the personal computer 15 and is received and processed without being filtered by the personal computer 15. In this way, packet transfer from the switching HUB 16 side to the personal computer 15 is performed through the bypass path in the Internet telephone 31.
[0071]
The received packet received by the transmission / reception circuit 42B is either P5 or P6.
[0072]
Regardless of which packet P5 or P6 is received, the transmission / reception circuit 42B supplies the received packet to both the FIFO 40B and the bypass FIFO 35.
[0073]
When the received packet is P5 (I, P), the accept signal supplied to the FIFO 40B by the transmission / reception circuit 42B is in an active state, and the FIFO 40B accumulates the P5. Therefore, the received packet P5 is transferred from the FIFO 40B to the bus interface 32. Supplied.
[0074]
As described above, the packet P5 transmitted to the switching HUB 16 via the FIFO 35 is filtered by the switching HUB 16 and discarded.
[0075]
On the contrary, when the received packet is P6 (S, P), the accept signal supplied to the FIFO 40B by the transmission / reception circuit 42B is inactive, and the FIFO 40B discards the P5, so that the received packet P5 is received from the FIFO 40B. It is not supplied to the bus interface 32.
[0076]
The received packet P6 supplied to and stored in the FIFO 35 is transmitted to the switching HUB 16 via the priority control circuit 41A and the transmission / reception circuit 42A, and the transmission designated by the transmission destination address S of the packet P6 is performed by the switching function of the switching HUB 16. It is delivered first, for example, to the telephone 4.
[0077]
That is, by transferring the packet P6, the personal computer 15 can transmit a packet to the switching HUB 16 through the bypass path in the Internet telephone 31. On the contrary, by transferring the packet P4, The personal computer 15 can receive a packet from the switching HUB 16 side through the bypass path in the telephone 31.
[0078]
(A-3) Effects of the first embodiment
According to this embodiment, when a switching HUB function of about 2 ports is built in like an Internet telephone, an extra load is not applied to the CPU (22), and an expensive switch LSI (large scale integrated circuit) is installed. Without using it, the Internet telephone itself can perform a simple switching operation.
[0079]
Further, since the CPU of the present embodiment only needs to process a packet whose destination address or source address designates itself, it is possible to minimize the consumption of processing capacity, and the personal computer can be connected to the Internet. It is possible to communicate with other devices connected to the switching HUB via the telephone (31).
[0080]
Furthermore, in this embodiment, it becomes possible to perform packet communication directly between the personal computer and the CPU without using a third party, and communication efficiency is increased.
[0081]
(B) Second embodiment
In a general switching HUB, communication mode negotiation (MII (Media Independent Interface) management function) is performed between a HUB port and a device connected thereto, and a mode capable of optimal and efficient data transmission is selected.
[0082]
Since the function of the MAC device 32 mounted on the Internet telephone 31 of the first embodiment can be regarded as an extremely simple switching HUB, the MAC device 32 belongs to the category of such a general switching HUB. Then, the communication mode setting of the telephone 31 is 100M full duplex communication with the HUB 16 side and 10M half duplex communication with the personal computer 15 as shown in FIG.
[0083]
Note that full-duplex communication is complete bi-directional communication that allows transmission and reception to be performed simultaneously in parallel.Half-duplex communication can only perform either transmission or reception at the same time. Is a two-way communication realized by temporally switching.
[0084]
If the personal computer 15 and the telephone 2 communicate with each other under the setting of 100M full-duplex communication on the HUB 16 side and 10M half-duplex communication on the personal computer 15 side, packets transmitted from the telephone 2 are transmitted via the telephone 31 to the personal computer 15. Sent to.
[0085]
However, since the throughput between the telephone 31 and the personal computer 15 is 10 Mbps, it is much smaller than 100 Mbps between the telephone 31 and the telephone 2, and during such communication, the FIFO 35 in the telephone 31 Packets addressed to the personal computer 15 that cannot be transmitted are accumulated.
[0086]
In addition, the communication between the telephone 31 and the personal computer 15 is half-duplex, and the communication between the telephone 31 and the switching HUB 16 is full-duplex, which substantially widens the throughput gap. It is a factor.
[0087]
In a general switching HUB equipped with a large number of LAN ports such as the switching HUB 16, it is possible to mount a large-scale memory that does not cause a packet overflow, assuming such a situation.
[0088]
However, if the size of the FIFO 35 is large enough to prevent packet overflow in the telephone 31 having only two LAN ports, the HUB port 50 and the personal computer port 51, the price of the telephone 31 is high. It is not preferable.
[0089]
Therefore, in the present embodiment, the communication mode of the two LAN ports in the telephone 31 is set to be the same, and the throughput of both is forcibly made uniform, so that this problem can be addressed using a small FIFO 35. Features.
[0090]
(B-1) Configuration and operation of the second embodiment
The hardware configuration of this embodiment is the same as that of the first embodiment.
[0091]
Therefore, FIG. 1, FIG. 3, and FIG. 5 are also explanatory diagrams of the present embodiment as they are.
[0092]
That is, the present embodiment and the first embodiment are almost the same in configuration and operation. Therefore, the packets used in this embodiment are the same as P1 to P6 shown in FIG.
[0093]
Below, only the point from which this embodiment is different from 1st Embodiment is demonstrated.
[0094]
Substantially this difference is limited to the portion related to the setting of the communication mode for the two LAN ports 50 and 51.
[0095]
FIG. 7 shows a flowchart regarding the communication mode setting of the present embodiment.
[0096]
This flowchart is composed of six steps S1 to S6.
[0097]
To set the LAN communication mode in the present embodiment, the above-described MII management function is used (IEEE802.3u).
[0098]
This function is a function in which PHYs connected together when LINK is established communicate their communication capabilities and automatically negotiate the best communication mode. The MII interface is an interface common to various configurations independent of the configuration of the physical layer.
[0099]
In FIG. 7, it is assumed that the telephone 31 is connected to the switching HUB (S1), negotiation is performed by MII between the switching HUB 16 and the HUB port 50 of the telephone 31, and 100M full duplex is selected as the communication mode (S2). .
[0100]
When this negotiation is performed for communication between the telephone 31 and the telephone 4, for example, a link is not established between the personal computer 15 and the telephone 31, and the communication of 100 Mbps full duplex is performed. In the mode, the packets P1 (S, I) and P3 (I, S) are exchanged (S3).
[0101]
On the other hand, if this negotiation is performed for communication between the personal computer 15 and the telephone 4, for example, step S3 is skipped and the process proceeds to step S4.
[0102]
At this time, a link is established not only between the telephone 31 and the switching HUB 16 but also between the personal computer 15 and the telephone 31, and the PC (personal computer port) 51 is provided with a PC (personal computer) 15. It is recognized that they are connected, and the branch on the Y (Yes) side in step S4 is selected.
[0103]
In response, in step S5, the communication mode between the personal computer 15 and the telephone 31 and the communication mode between the telephone 31 and the switching HUB 16 are set to 10M half-duplex by the MII management function.
[0104]
In the next step S 6, communication between the personal computer 15 and the telephone 4 is performed via the telephone 31 in 10M half duplex.
[0105]
In this communication, the communication mode between the ports is 10 Mbps, and half duplex is made uniform, so that the packets P4 (P, S) and P6 (S, P) exchanged between the personal computer 15 and the telephone 4 are performed. Is stored in the FIFO 35 to the minimum necessary, and even with a small-capacity FIFO 35, packet overflow is unlikely to occur.
[0106]
(B-2) Effects of the second embodiment
According to this embodiment, the same effect as that of the first embodiment can be obtained.
[0107]
In addition, in this embodiment, even if the memory capacity (capacity of the FIFO 35) built into the MAC device is reduced, packet loss is unlikely to occur, and a low-cost Internet telephone is provided for high communication quality during packet mediation. can do.
[0108]
Also, the fact that the memory capacity can be reduced means that the required function can be easily achieved with a small built-in memory without using an external memory when the MAC device (32) is made into LSI. That is.
[0109]
(C) Other embodiments
In the first and second embodiments, an Internet telephone equipped with both an uplink LAN port and a LAN port for a personal computer has been described as an example. However, the present invention can be applied to other than the Internet telephone. .
[0110]
For example, the present invention can also be applied to a terminal adapter equipped with two LAN ports.
[0111]
Also, the number of LAN ports to be installed is not limited to two, but may be about three, for example.
[0112]
Further, as specific examples of LAN ports, 10BASE-T, 100BASE-T, and the like can be used, as well as an optical fiber distributed interface (FDDI) system, 100VG-AnyLAN, ATM-LAN and other networks. Any suitable port configuration can be used.
[0113]
The main point of the second embodiment is that the communication modes of the two LAN ports mounted on the Internet telephone 31 are made uniform, but the main point can be applied to other than the Internet telephone 31. Even in that case, the usefulness is not lost.
[0114]
For example, this point may be applied to the telephone 1 which sends the voice packet described in the column of the problem to be solved to the computer network 10 in preference to the computer communication packet. Can reduce the capacity of the buffer memory in the MAC 23 (corresponding to the FIFOs 40A and 40B of the telephone 31).
[0115]
That is, the present invention is connected to the first interface means for connecting to the network, the second interface means for transmitting and receiving voice packets, the third interface means for computer data communication, and the second interface means. A central processing unit, a first interface means capable of communicating in a first communication mode including conditions relating to data transfer capacity for connection to a network, and a second for transmitting and receiving voice packets The third interface means for communicating in the second communication mode having at least a data transfer capacity smaller than that of the first communication mode for the computer data communication, the first interface means and the third interface. Temporary storage for temporarily accumulating data transmitted between means And a stage, a first interface means and the third communication device capable of mediating computer data communication performed by using the interface means, and, for the network using these communication devices, can be widely applied.
[0116]
【The invention's effect】
As described above, according to the first invention, a simple switch operation can be performed with a low price and a small configuration.
[0117]
According to the first invention, the communication device accommodates the computer (terminal) and the data stored in the communication device without going through a third party and without applying an extra load to the central processing unit of the communication device. Communication is also possible.
[0118]
Further, according to the second invention, even if the capacity of the temporary storage means for temporarily storing data transmitted between the first interface means and the third interface means is reduced, the data loss The rate can be kept low, and the communication quality is high for a small scale.
[0119]
In addition, the network according to the third invention can enjoy the advantages of the communication devices of the first and second inventions.
[Brief description of the drawings]
FIG. 1 is a schematic diagram showing an internal configuration of a MAC device built in an Internet telephone according to first and second embodiments.
FIG. 2 is a schematic diagram showing the internal configuration and operation of a conventional Internet telephone.
FIG. 3 is a schematic diagram showing an overall configuration of a computer network according to the related art and an embodiment.
FIG. 4 is a schematic diagram showing the internal configuration and operation of another conventional Internet telephone.
FIG. 5 is a schematic diagram showing an internal configuration of an Internet telephone according to the first and second embodiments.
FIG. 6 is a schematic diagram showing a packet processed by the Internet telephone according to the first and second embodiments.
FIG. 7 is a flowchart for explaining the operation of the second embodiment;
[Explanation of symbols]
1-4, 31 ... telephone (Internet telephone), 10, 30 ... computer network, 11-14, 17 ... LAN cable, 15 ... personal computer terminal, 16 ... switching HUB, 22 ... CPU, 24, 25 ... PHY, 32 ... MAC device, 33, 34 ... Element MAC, 35, 40A, 40B ... FIFO, 36 ... Bus interface, 41A, 41B ... Priority control circuit, 50, 51 ... LAN port.

Claims (4)

First interface means for connecting to a network, second interface means for voice packet transmission / reception, third interface means for computer data communication, and a central processing unit connected to the second interface means In a communication device comprising:
A first medium access controller for connecting the first interface means and the second interface means;
A second medium access control unit for connecting the third interface unit and the second interface unit;
By connecting the inside of the second medium access control unit and the inside of the first medium access control unit, the second interface unit is interposed between the first interface unit and the third interface unit. And a bypass means for connecting via a short path. The communication device according to claim 1.
The first and second medium access control units are:
Priority control for giving priority to the voice packet supplied from the second interface means over the packet for computer data communication supplied from the third interface means and sending it to the first or third interface means of the destination. A communication device comprising means. In order to connect to the network, the first interface means capable of communicating in the first communication mode including the condition relating to the data transfer capacity, the second interface means for voice packet transmission / reception, and the first interface means for computer data communication Third interface means for communicating in the second communication mode having at least a data transfer capacity smaller than that of the communication mode, and data transmitted between the first interface means and the third interface means are temporarily stored. And a temporary storage means, and a communication apparatus capable of mediating computer data communication performed using the first interface means and the third interface means,
Communication for changing the first communication mode to correspond to the second communication mode when the computer data communication is performed between the computer terminal connected to the third interface means and the network. A communication device comprising mode change means. A communication device according to any one of claims 1 to 3;
A line concentrator connected to the first interface means of the communication device;
A network comprising: a communication computer terminal connected to a third interface means of the communication device.

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