CN114070823A

CN114070823A - Session establishment control method, electronic device, and computer-readable storage medium

Info

Publication number: CN114070823A
Application number: CN202111328690.XA
Authority: CN
Inventors: 李鑫; 邢园园; 王旻聪
Original assignee: Beijing Nera Stentofon Communication Equipment Co Ltd
Current assignee: Beijing Nera Stentofon Communication Equipment Co Ltd
Priority date: 2021-11-10
Filing date: 2021-11-10
Publication date: 2022-02-18
Anticipated expiration: 2041-11-10
Also published as: CN114070823B; WO2023082676A1

Abstract

The invention provides a session establishment control method, electronic equipment and a computer readable storage medium, wherein the method comprises the following steps: in response to receiving an instruction message that a calling UE requests to establish a session, determining whether a called UE is registered in a calling CSCF; the calling CSCF is a CSCF registered by calling user equipment; if the called UE is not registered in the calling CSCF, inquiring whether an address of the called CSCF exists in a session cache region; the called CSCF is a CSCF registered by called UE, the session cache region is used for storing relevant information of historical sessions, and the relevant information of the historical sessions comprises addresses of the CSCFs corresponding to the called UE; and if the address of the called CSCF exists in the session cache region, sending the instruction message for requesting to establish the session to the address of the called CSCF.

Description

Session establishment control method, electronic device, and computer-readable storage medium

Technical Field

The present invention relates to the field of communications, and in particular, to a session establishment control method, an electronic device, and a computer-readable storage medium.

Background

An Internet Protocol (IP) Multimedia Subsystem (IMS) is a brand new Multimedia service form based on a Session Initiation Protocol (SIP), a design method of separating services, control and bearing is adopted on the basis of soft switch, an important mode of differentiated services such as triple fusion of voice, data and video is introduced, diversified and differentiated converged communication services are provided for industry dedicated communication, and various access modes can be supported, so that different users can access an IMS network, and the requirement of the users for enjoying rich service services is met.

With the gradual application of the IMS technology in the field of industrial dedicated communication, the change of the industrial communication mode will inevitably place higher demands on network bandwidth, call delay, and call quality, and particularly, information related to the industrial application, such as administrative office data, production and management data, needs to be efficiently acquired, transmitted, and analyzed. The SIP protocol is used as a main signaling Control protocol of the IMS, and is applied to IMS Session Control, mobility management, and end-to-end Quality of Service (QoS) Control, for example, SIP is mainly used for Call Session Control functions (CSCF, Call Session Control Function) of a network key entity in IMS Session Control, such as communication between a Serving CSCF (S-CSCF, Serving CSCF), a Proxy CSCF (P-CSCF, Proxy CSCF), and an inquiring CSCF (I-CSCF, interworking CSCF); SIP enables a user to be contacted by binding his address record with a host IP address; SIP supports end-to-end QoS for sessions through Session Description Protocol (SDP) and invite/answer modes.

Disclosure of Invention

The invention provides a session establishment control method, electronic equipment and a computer-readable storage medium.

In a first aspect, the present invention provides a session establishment control method, where the method includes:

in response to receiving an instruction message that a calling User Equipment (UE) requests to establish a session, determining whether a called UE is registered in a calling call session control function entity (CSCF); the calling CSCF is a CSCF registered by calling UE;

if the called UE is not registered in the calling CSCF, inquiring whether an address of the called CSCF exists in a session cache region; the called CSCF is a CSCF registered by called UE, the session cache region is used for storing relevant information of historical sessions, and the relevant information of the historical sessions comprises addresses of the CSCFs corresponding to the called UE;

and if the address of the called CSCF exists in the session cache region, sending the instruction message for requesting to establish the session to the address of the called CSCF.

Further, if the called UE is registered in the calling CSCF, the session establishment control method further includes:

resources are allocated for the session to establish the session.

Further, if the address of the called CSCF does not exist in the session cache, the session establishment control method further includes:

inquiring a domain name resolution system (DNS) to obtain the address of a called CSCF;

sending the instruction message of requesting to establish the session to the address of the called CSCF;

and if the session is successfully established, storing the address of the called CSCF in the session cache region.

In some embodiments, the session establishment control method is implemented based on a compression coding algorithm.

Further, before the step of confirming whether the called UE is registered in the calling CSCF in response to receiving an instruction message that the calling UE requests to establish a session and implementing the session establishment control method based on the compression coding algorithm, the session establishment control method includes:

obtaining a preloaded text according to an instruction and a common phrase in a protocol standard, wherein the instruction is an instruction required for realizing the session establishment control method;

performing lossless compression on the preloaded text by adopting a compression algorithm to obtain a compressed code word;

and coding the compressed code words by adopting a coding algorithm to obtain a compressed coding message corresponding to each instruction and the common phrase.

Further, the lossless compression of the preloaded text by using a compression algorithm to obtain a compressed codeword includes:

adding the instruction and the common phrases into a first array to obtain a static dictionary;

and executing the compression algorithm according to the static dictionary, and compressing to obtain a compressed code word.

Further, the encoding the compressed code word by using an encoding algorithm to obtain a compressed encoded message corresponding to each protocol standard message includes:

adding the compressed code words and the occurrence times of the compressed code words into a second array;

and executing the coding algorithm according to the second array to obtain a compressed coding message corresponding to each instruction and the common phrase.

Optionally, the compression algorithm is a string table compression algorithm, and the encoding algorithm is an arithmetic encoding algorithm.

In a second aspect, the present invention provides an electronic device, comprising:

one or more processors;

a memory on which is stored one or more programs that, when executed by the one or more processors, cause the one or more processors to implement the session establishment control method according to any one of the first aspects;

one or more I/O interfaces connected between the processor and the memory and configured to enable information interaction between the processor and the memory.

In a third aspect, the present invention provides a computer-readable storage medium having stored thereon a computer program which, when executed by a processor, implements a session establishment control method according to any one of the first aspects.

Aiming at the contradiction between the limited bandwidth and the SIP redundant message caused by the increase of the number of users, the method aims to solve the problem that the SIP session performance is sharply reduced due to the increase of the packet loss rate and the increase of the retransmission delay. According to the session establishment control method provided by the invention, when the calling UE and the called UE are both in the same CSCF range, the interaction process between the calling CSCF and the called CSCF is saved, and when the calling UE and the called UE are not in the same CSCF range, the address of the called CSCF is quickly confirmed according to the historical session information of the local session cache region, so that the query process of the called CSCF is simplified, the number of redundant messages is reduced, the bandwidth pressure is relieved, and the SIP session performance is improved.

Drawings

Fig. 1 is a flowchart of a session establishment control method according to an embodiment of the present invention.

Fig. 2 is a flowchart of another session establishment control method according to an embodiment of the present invention.

Fig. 3 is a flowchart of a further session establishment control method according to an embodiment of the present invention.

Fig. 4 is a flowchart of a session establishment control method according to another embodiment of the present invention.

Fig. 5 is a flowchart of some steps in a session establishment control method according to another embodiment of the present invention.

Fig. 6 is a flowchart of some steps in a further session establishment control method according to an embodiment of the present invention.

Fig. 7 is a timing diagram of a session establishment procedure provided by an embodiment of the present invention.

FIG. 8 is a flowchart of compression encoding of instructions according to an embodiment of the present invention.

Fig. 9 is a schematic diagram of an electronic device according to an embodiment of the present invention.

Fig. 10 is a schematic diagram of a computer-readable storage medium according to an embodiment of the present invention.

Detailed Description

It should be understood that the specific embodiments described herein are merely illustrative of the invention and are not intended to limit the invention.

In the following description, suffixes such as "module", "part", or "unit" used to denote elements are used only for facilitating the explanation of the present invention, and have no peculiar meaning in itself. Thus, "module", "component" or "unit" may be used mixedly.

The inventor of the invention sees that the IMS provides diversified and differentiated converged communication service for the special communication of the industry, supports various access modes, meets the abundant service requirements of users, and simultaneously sees the problem that the existing IMS mechanism is gradually exposed. In an IMS session establishment mechanism, SIP signaling is more, so that the session establishment time is too long, and the following problems exist:

(1) along with the increase of the number of users and the expansion of SIP message contents, the contradiction between the limited bandwidth and the SIP redundant message is increasingly prominent, so that the packet loss rate is increased and the retransmission delay is increased, and further the SIP session performance is sharply reduced;

(2) the existing SIP session establishment flow specification does not consider the session establishment request between users in the same S-CSCF service range, and still needs a Domain Name Resolution (DNS) query process and an S-CSCF allocation process to determine the address of the S-CSCF serving as a called party in the session establishment process, thereby increasing unnecessary interaction processes and further increasing the SIP session delay.

The inventor considers starting from two key points of the number and the length of the SIP messages, reduces the number of redundant messages by simplifying the flow, and further reduces the length of the messages by compressing and encoding the instruction messages, thereby relieving the bandwidth pressure and improving the performance of the SIP session.

In a first aspect, an embodiment of the present invention provides a session establishment control method, as shown in fig. 1, where the method includes the following steps:

in step S100, in response to receiving an instruction message that a calling user equipment UE requests to establish a session, it is determined whether a called UE is registered in a calling call session control function entity CSCF; the calling CSCF is a CSCF registered by calling UE;

in step S200, if the called UE is not registered in the calling CSCF, querying whether an address of the called CSCF exists in a session cache region; the called CSCF is a CSCF registered by called UE, the session cache region is used for storing relevant information of historical sessions, and the relevant information of the historical sessions comprises addresses of the CSCFs corresponding to the called UE;

in step S300, if the address of the called CSCF exists in the session cache, the instruction message requesting to establish the session is sent to the address of the called CSCF.

The inventor finds that according to the communication habits of people, the probability of making a call to a nearby terminal is relatively high, and almost all users have some UEs frequently called, and the ratio of the number of times of calling the UEs frequently called to the total number of calls is also high. Therefore, in the process of session establishment, two places in the flow of inquiring the address of the called CSCF can be simplified, and the effect of reducing the number of redundant messages is achieved.

Firstly, when a calling User Equipment (UE) sends an INVITE (INVITE) message to a calling CSCF, the calling CSCF may confirm whether the called UE is also registered in the calling CSCF according to information of the called UE, that is, judge whether the calling CSCF and the called CSCF are the same CSCF at this time, and if the two are the same CSCF, query the called CSCF in a subsequent session establishment procedure, and interaction of instruction messages between a large number of calling CSCFs and called CSCFs in a session negotiation process may be omitted, as long as necessary steps such as resource allocation and state machine change are retained, so that interaction of a large number of instruction messages may be reduced.

Secondly, a session buffer area can be set on the calling CSCF, when the calling CSCF and the called CSCF are not the same CSCF, the calling CSCF can query whether the current called UE and the called CSCF corresponding thereto exist in the history session through the session buffer area, and if so, the address of the called CSCF can be directly obtained from the session buffer area, thereby omitting steps of querying the called CSCF through the DNS, forwarding messages to the called side, and the like, and reducing instruction messages generated in related steps.

In step S200, the called UE is not registered in the calling CSCF, and although the calling CSCF and the called CSCF are not in the same CSCF service range, the address of the called CSCF may be queried in the session buffer in step S300. If the address of the called CSCF can be found in the historical session information stored in the session cache region, the calling CSCF directly sends an INVITE message to the address of the called CSCF.

With the increase of the session establishment times, the historical session information stored in the session cache region will be more and more, and the probability of being able to query the called CSCF is higher and higher, so that the redundant messages caused by querying the called CSCF can be reduced to a great extent. By judging the calling UE and the called UE which belong to the same CSCF service range and inquiring the historical conversation information, the interaction of redundant messages can be greatly reduced, and the effect of relieving bandwidth pressure is achieved.

Further, as shown in fig. 2, if the called UE is registered in the calling CSCF, the session establishment control method further includes:

in step S210, resources are allocated for the session to establish the session.

Although in the related art, the CSCF also allocates resources for the session, it should be noted that in step S210, when the calling UE and the called UE are both within the service range of the same CSCF, it is not necessary to query the address of the called CSCF, query the called CSCF in the session establishment procedure, and perform a large number of instruction message interactions between the calling CSCF and the called CSCF in the session negotiation process, and the session can be directly established for the calling UE and the called UE as long as the necessary steps of resource allocation, state machine change, and the like are reserved.

Further, as shown in fig. 3, if the address of the called CSCF does not exist in the session cache, the session establishment control method further includes:

in step S310, a domain name resolution DNS is queried to obtain an address of the called CSCF;

in step S320, sending the instruction message requesting to establish the session to the address of the called CSCF;

in step S330, if the session is successfully established, the address of the called CSCF is stored in the session cache.

When the current called UE and the corresponding called CSCF thereof cannot be found in the historical session information of the session cache region, the address of the called CSCF can be inquired through the DNS, and then an instruction message for requesting to establish the session is sent to the inquired address of the called CSCF.

It should be noted that, when the session is successfully established, the current session information, including the device identifier, address, and other information related to the called UE and the called CSCF, is stored in the session cache area in the form of a historical session. Although the probability of finding the historical session is low at first, as the number of established sessions increases, the number of historical session information stored in the session cache area increases, and the probability of being able to find the called CSCF increases. Since almost all users have some UEs frequently called and the ratio of the number of times of calling the UEs frequently called to the total number of times of calling is also high, the address of the called CSCF can be quickly found through the historical session information in the session cache, and a large number of flows for inquiring the address of the called CSCF and related interaction flows can be simplified.

Reducing the length of the instructions while reducing the number of instruction messages may also relieve bandwidth pressure.

Further, as shown in fig. 4, before the step of confirming whether the called UE is registered in the calling CSCF in response to receiving the instruction message that the calling UE requests to establish the session and implementing the session establishment control method based on the compression coding algorithm, the session establishment control method further includes:

in step S410, a preloaded text is obtained according to an instruction and a common phrase in a protocol standard, where the instruction is an instruction required for implementing the session establishment control method;

in step S420, lossless compression is performed on the preloaded text by using a compression algorithm to obtain a compressed codeword;

in step S430, the compressed code word is encoded by using an encoding algorithm, and a compressed encoded message corresponding to each instruction and the common phrase is obtained.

Before establishing a session, combining the communication service characteristics of an industrial IMS system, preloading daily instruction messages and common phrases of an SIP protocol, compressing and encoding the SIP messages through a compression algorithm and an encoding algorithm to obtain compressed encoding messages corresponding to the instructions and the common phrases in a protocol standard. In the session establishment process, unified compressed coding messages are adopted among the UE, CSCF and other devices, and the compressed coding messages with fewer bytes express the same meaning as the instruction and common phrases in the protocol standard, so that various processes including the steps S100-S300 of requesting session establishment, inquiring DNS, obtaining the address of the called CSCF, PRACK notification, Ringing notification and the like are realized. Because all the instructions are compressed and coded, the length of each instruction message of each user is greatly reduced, so that the effect of relieving bandwidth pressure can be achieved, and the session establishment delay caused by huge message transmission is reduced.

Further, as shown in fig. 5, step S420 performs lossless compression on the preloaded text by using a compression algorithm to obtain a compressed codeword, which specifically includes:

in step S421, adding the instruction and the common phrase into the first array to obtain a static dictionary;

in step S422, the compression algorithm is executed according to the static dictionary, and a compressed codeword is obtained by compression.

Further, as shown in fig. 6, the encoding the compressed code word by using an encoding algorithm to obtain a compressed encoded message corresponding to each protocol standard message includes:

in step S431, adding the compressed codeword and the number of occurrences of the compressed codeword to a second array;

in step S432, according to the second array, the coding algorithm is executed to obtain a compressed coding message corresponding to each instruction and the common phrase.

Firstly, a first array is constructed according to instructions and common phrases in a preloaded protocol standard, and a static dictionary is obtained after all the instructions and phrases are added. Then, the static dictionary is compressed according to a predetermined compression algorithm, such as a string table compression algorithm (LZW, Lempel-Ziv-Welch Encoding), to obtain a compressed codeword.

And constructing a second number group according to the compressed code words and the occurrence times of the compressed code words, constructing a tree by using the second number group according to the total occurrence times of the code words, and encoding according to a preset encoding algorithm, such as arithmetic number encoding, to obtain a compressed encoding message.

It should be noted that the compressed and encoded message obtained by compressing and encoding the instruction and the common phrase in the protocol standard is not limited to each step used in the session establishment control method of the present invention, and for all scenes using SIP messages, the unified compressed and encoded message obtained by pre-calculation can be used for interaction, which plays a role in relieving bandwidth pressure.

The session establishment control method according to the first aspect of the present invention is actually described below with reference to 2 embodiments. . . The specific application of the process is introduced.

Example 1

The CSCF in embodiment 1 is further refined into a P-CSCF, an S-CSCF, and an I-CSCF according to the session establishment procedure, and the specific process of session establishment is as follows:

when a calling UE A needs to establish a session with a called UE B, the UE A generates a SIP-INVITE request message. The SIP messages in this embodiment 1 are compressed encoded messages obtained by encoding the lossless compression and encoding algorithms by using the improved LZW algorithm, and are forwarded to the calling S-CSCF a of the originating home network through the P-CSCF a of the originating visited network, where the S-CSCF a executes the service invocation process.

The originating calling S-CSCF A receives the session establishment request of the UE A and checks whether the UE B is currently in the same S-CSCF A service range. If the calling UE A and the called UE B belong to the same service range of the S-CSCF A, resources are distributed for the calling UE A and the called UE B, and session connection is established between the UE A and the UE B. As shown in (1) to (4) in fig. 7.

And the calling S-CSCF A inquires whether the historical session information of the local session cache region has the address information of the called S-CSCF for providing service for the called UE B. If so, the calling S-CSCF A can adopt the address information of the called S-CSCF B where the called UE B is located, and the calling S-CSCF A sends an INVITE request to the called S-CSCF B to establish session connection; if not, the calling S-CSCF A initiates a query DNS to obtain the address information of the called I-CSCF B, the INVITE request is sent to the called I-CSCF B, the called I-CSCF B forwards the INVITE request to the called S-CSCF B to establish session connection, and the calling S-CSCF A obtains the address information of the called S-CSCF B from the first successful processing response and stores the address information in a local session cache region. As shown in (5) - (7) of fig. 7.

The called I-CSCF B obtains the address of the called S-CSCF B serving it from the HSS of the terminating network via a Diameter message. As shown in (8) - (9) of fig. 7.

And the called I-CSCF B sends the compressed INVITE message to a called S-CSCF B serving the called, and the called S-CSCFB routes the INVITE message to the UE B through a called P-CSCF B of a receiving terminal visiting network after finishing the service calling. As shown in (10) - (15) of fig. 7.

In the above steps, after receiving the INVITE message, each IMS entity responds with a 180-time temporary response message, and after receiving the first 180, UE a starts resource reservation. The calling INVITE message carries the originating SDP and uses the QoS precondition extension, which indicates that the called UE B cannot ring to the user until the QoS resources of the session are available.

A 183 Session Progress (Session Progress) temporary response message returned by the receiving end, which carries an SDP containing media parameters acceptable by the receiving end, performs media negotiation and starts to execute resource reservation on an access network; the calling side informs the called side of the acceptance of the 183 response with the SDP sent by the called side through the PRACK message and starts resource reservation, and the called side starts resource reservation after receiving the PRACK and sending 200 OK. As shown in (16) - (31) of fig. 7.

After the resource reservation of the UE B is completed, Ringing is started to the user and the UE A is informed that the called party rings through a 180Ringing message. After the called side selects answering, the UE B sends a final response 200OK message of the message. And the UE A receives the message and then confirms through the ACK message, thereby completing the establishment of the calling and called sessions. As shown in (32) - (52) of fig. 7.

Since (16) - (21), (22) - (26), (27) - (31), (32) - (37), (38) - (42), (43) - (47) in fig. 7 all issue the same message from one end UE to the device between the other end UEs, the description is incorporated in the figures for the sake of picture clarity.

Example 2

The SIP messages in embodiment 1 are all compression-encoded messages obtained by performing lossless compression and encoding using the improved LZW algorithm. The specific compression and encoding process is shown in fig. 8.

1. And preloading daily instruction messages and common phrases of the SIP session by combining the communication service characteristics of the industrial IMS system.

2. The array includes two parts, Key and Value. Key is index, Value is content of instruction or phrase.

3. C (get) (in) is executed to read in the first character and Pcode (C) is executed.

4. Reading in the next character, i.e. executing C ═ get (in).

5. K is executed as Pcode < < ByteSize + C.

6. And assigning the corresponding Value to the Pcode according to the Key matched by the K.

7. Judging whether the K is in the SIP keyword array or not, and if yes, turning to the step 3; if "no", the next step, step 8, is performed.

8. The result is added to the corresponding array and to the static dictionary, and then Pcode is performed equal to 0.

9. Judging whether characters are still input in the preloaded text, and turning to the step 3 if the characters are still input in the preloaded text; if "no", the next step, step 10, is performed.

10. Adding the SIP static dictionary ends.

11. The LZW compression algorithm is performed and the codeword is output.

12. Array A stores the codewords from the LZW output, and the array contains the input codewords and the number of occurrences of the codewords.

13. And counting the number of times of the code word in the array A and generating an array B, wherein the array B comprises the code word and the total number of times of the code word.

14. And constructing a tree by the array B, carrying out arithmetic coding and outputting a coding result.

15. The SIP message encoding is ended.

At this point, a compressed encoded message is obtained. The compressed and coded message is uniformly deployed on related equipment in the network, the compressed and coded message is automatically converted into the compressed and coded message when the instruction message is issued, and the equipment which receives the compressed and coded message processes the compressed and coded message according to the instruction message in the corresponding protocol standard after translating the compressed and coded message.

Optionally, a flag enabling the compression coding message may be further set in the session negotiation information, so as to determine whether the peer device supports the compression coding message. If the opposite terminal equipment supports the compressed coding message, the compressed coding message is issued, and if the opposite terminal equipment does not support the compressed coding message, the instruction of the protocol standard is still issued.

In a second aspect, an embodiment of the present invention provides an electronic device, as shown in fig. 9, including:

one or more processors 501;

a memory 502 on which one or more programs are stored, which when executed by the one or more processors, cause the one or more processors to implement the session establishment control method as described in any one of the above first aspects;

one or more I/O interfaces 503 coupled between the processor and the memory and configured to enable information interaction between the processor and the memory.

The processor 501 is a device with data processing capability, and includes but is not limited to a Central Processing Unit (CPU) and the like; memory 502 is a device having data storage capabilities including, but not limited to, random access memory (RAM, more specifically SDRAM, DDR, etc.), Read Only Memory (ROM), Electrically Erasable Programmable Read Only Memory (EEPROM), FLASH memory (FLASH); an I/O interface (read/write interface) 503 is connected between the processor 501 and the memory 502, and can realize information interaction between the processor 501 and the memory 502, which includes but is not limited to a data Bus (Bus) and the like.

In some embodiments, the processor 501, memory 502, and I/O interface 503 are interconnected by a bus 504, which in turn connects with other components of the computing device.

In a third aspect, a computer-readable storage medium, as shown in fig. 10, has a computer program stored thereon, and when executed by a processor, the computer program implements the session establishment control method of any one of the first aspect.

Aiming at the contradiction between the limited bandwidth and the SIP redundant message caused by the increase of the number of users, the method aims to solve the problem that the SIP session performance is sharply reduced due to the increase of the packet loss rate and the increase of the retransmission delay. The session establishment control method provided by the invention omits the interaction process between the calling CSCF and the called CSCF when the calling UE and the called UE are both in the same CSCF range, quickly confirms the address of the called CSCF according to the historical session information of the local session cache region when the calling UE and the called UE are not in the same CSCF range, simplifies the query process of the called CSCF, reduces the number of redundant messages, further reduces the length of the SIP messages through the compression and encoding of the SIP messages, relieves the bandwidth pressure from the two aspects of the number of the messages and the length of the messages, and improves the session performance of the SIP.

One of ordinary skill in the art will appreciate that all or some of the steps of the methods, systems, functional modules/units in the devices disclosed above may be implemented as software, firmware, hardware, and suitable combinations thereof.

In a hardware implementation, the division between functional modules/units mentioned in the above description does not necessarily correspond to the division of physical components; for example, one physical component may have multiple functions, or one function or step may be performed by several physical components in cooperation. Some or all of the physical components may be implemented as software executed by a processor, such as a central processing unit, digital signal processor, or microprocessor, or as hardware, or as an integrated circuit, such as an application specific integrated circuit. Such software may be distributed on computer readable media, which may include computer storage media (or non-transitory media) and communication media (or transitory media). The term computer storage media includes volatile and nonvolatile, removable and non-removable media implemented in any method or technology for storage of information such as computer readable instructions, data structures, program modules or other data, as is well known to those of ordinary skill in the art. Computer storage media includes, but is not limited to, RAM, ROM, EEPROM, flash memory or other memory technology, CD-ROM, Digital Versatile Disks (DVD) or other optical disk storage, magnetic cassettes, magnetic tape, magnetic disk storage or other magnetic storage devices, or any other medium which can be used to store the desired information and which can accessed by a computer. In addition, communication media typically embodies computer readable instructions, data structures, program modules or other data in a modulated data signal such as a carrier wave or other transport mechanism and includes any information delivery media as known to those skilled in the art.

The preferred embodiments of the present invention have been described above with reference to the accompanying drawings, and are not to be construed as limiting the scope of the invention. Any modifications, equivalents and improvements which may occur to those skilled in the art without departing from the scope and spirit of the present invention are intended to be within the scope of the claims.

Claims

1. A session establishment control method, the method comprising:

in response to receiving an instruction message that a calling User Equipment (UE) requests to establish a session, determining whether a called UE is registered in a calling call session control function entity (CSCF); the calling CSCF is a CSCF registered by calling user equipment;

2. The session establishment control method according to claim 1, wherein if the called UE is registered in the calling CSCF, the session establishment control method further comprises:

resources are allocated for the session to establish the session.

3. The session establishment control method according to claim 1, wherein if the address of the called CSCF does not exist in the session cache, the session establishment control method further comprises:

4. A session establishment control method according to any one of claims 1 to 3, wherein said session establishment control method is implemented based on a compression coding algorithm.

5. The session establishment control method according to claim 4, wherein, before said step of confirming whether the called UE is registered at the calling CSCF in response to receiving an instruction message that the calling UE requests establishment of the session, said session establishment control method implementing said session establishment control method based on said compression coding algorithm, said session establishment control method further comprises:

6. The session establishment control method according to claim 5, wherein said lossless compressing said preloaded text by using a compression algorithm to obtain a compressed codeword comprises:

7. The session establishment control method according to claim 5, wherein said encoding said compressed code word by using an encoding algorithm to obtain a compressed encoded message corresponding to each protocol standard message comprises:

8. The session establishment control method according to claim 5,

the compression algorithm is a string table compression algorithm, and the coding algorithm is an arithmetic coding algorithm.

9. An electronic device, comprising:

one or more processors;

a memory on which one or more programs are stored, which when executed by the one or more processors, cause the one or more processors to implement the session establishment control method according to any one of claims 1 to 8;

10. A computer-readable storage medium having stored thereon a computer program which, when executed by a processor, implements a session establishment control method according to any one of claims 1 to 8.