在IMS/SIP支持的VOLTE等业务中经常要进行控制面和用户面数据的传递，那么这些数据在IP网络的传递时就会遇到TCP/UDP端口的选择问题，本文根据实际举例其选择过程：

1.TCP/UDP应用 

        如下图所示:用户A(UA1)首先通过CSCF发送TCP请求给用户B(UA2)，再通过CSCF发送UDP请求给用户B(UA2)

2.场景1（注册和应答） 

(A) Transmission Control Protocol, (B) Src Port: 50000 , (C) Dst Port: 55062 ,

REGISTER sip:one.att.net SIP/2.0

Via: SIP/2.0/TCP [3000::2:5547:21cb:7edf:9962]:(D)50001;

       branch=z9hG4bK44ccabd6a7f33104360e9ae78ce1ac0d;rport

Max-Forwards: 70

Contact: <sip:310410123456789@[3000::2:5547:21cb:7edf:9962]:(E)50001;(F) transport=tcp>;

            +g.3gpp.smsip;

            +g.3gpp.icsi-ref="urn%3Aurn-7%3A3gpp-service.ims.icsi.mmtel";

            +sip.instance="<urn:gsma:imei:00440224-264925-0>"

To: <sip:310410123456789@one.att.net>

From: <sip:310410123456789@one.att.net>;tag=4887461765a4b2fc-d90ef734.0

Call-ID: 54df046e-10604c38-9f947b79@3000::2:5547:21cb:7edf:9962

CSeq: 2 REGISTER

Expires: 600000

Allow: INVITE, ACK, CANCEL, OPTIONS, BYE, REFER, NOTIFY, MESSAGE, SUBSCRIBE, INFO

User-Agent: IM-client/OMA1.0 TEST-IMS

Authorization: Digest username="310410123456789@private.att.net", realm="one.att.net",

nonce="1XcMbTY+MMNkpAePG/jtOm4yOzbFNdVV1XYObjNi45E=", uri="sip:one.att.net", response="7a87c22410c409ffef55ea37b41bfe4c",

algorithm=AKAv1-MD5,

cnonce="b4972c8ee817300a7ff36ed1cbd59be", opaque="09e88aef2....", qop=auth, nc=00000001

Security-Verify: ipsec-3gpp; ealg=null; alg=hmac-sha-1-96; spi-c=98765431; spi-s=87654321;

(G)port-c=55063;

(H)port-s=55062;

q=0.9,ipsec-3gpp; ealg=null; alg=hmac-md5-96; spi-c=98765431; spi-s=87654321;

(I)port-c=55063;

(J)port-s=55062;

q=0.7

P-Access-Network-Info: 3GPP-E-UTRAN-FDD; utran-cell-id-3gpp=31041000040000004

Supported: sec-agree, path

Proxy-Require: sec-agree

Security-Client: ipsec-3gpp; ealg=aes-cbc;

alg=hmac-sha-1-96; spi-c=41064354; spi-s=34933966;

(K)port-c=50000;

(L)port-s=50001;

prot=esp; mod=trans, ipsec-3gpp;

ealg=aes-cbc; alg=hmac-md5-96; spi-c=41064354; spi-s=34933966;

(M)port-c=50000;

(N)port-s=50001;

prot=esp; mod=trans, ipsec-3gpp; ealg=des-ede3-cbc;

alg=hmac-sha-1-96; spi-c=41064354; spi-s=34933966;

(O)port-c=50000;

(P)port-s=50001;

prot=esp; mod=trans, ipsec-3gpp; ealg=des-ede3-cbc; alg=hmac-md5-96;

spi-c=41064354; spi-s=34933966;

(Q)port-c=50000;

(R)port-s=50001;

prot=esp; mod=trans, ipsec-3gpp;

ealg=null; alg=hmac-sha-1-96; spi-c=41064354; spi-s=34933966;

(S)port-c=50000;

(T)port-s=50001;

prot=esp; mod=trans, ipsec-3gpp; ealg=null; alg=hmac-md5-96;

spi-c=41064354; spi-s=34933966;

(U)port-c=50000;

(V)port-s=50001;

prot=esp; mod=trans

Require: sec-agree

Content-Length: 0

(1)Transmission Control Protocol, (2)Src Port: 55062, (3)Dst Port: 50000, Seq: 1, Ack: 2279, Len: 655

SIP/2.0 200 OK

Via: SIP/2.0/TCP [3000::2:5547:21cb:7edf:9962]:(4)50001;

      branch=z9hG4bK44ccabd6a7f33104360e9ae78ce1ac0d;rport

To: <sip:310410123456789@one.att.net>; tag=ATL2604_d9bc654771cd

From: <sip:310410123456789@one.att.net>;tag=4887461765a4b2fc-d90ef734.0

Call-ID: 54df046e-10604c38-9f947b79@3000::2:5547:21cb:7edf:9962

CSeq: 2 REGISTER

Contact: <sip:310410123456789@[3000::2:5547:21cb:7edf:9962]:(5)50001;(6)transport=tcp>; expires=1200

P-Associated-URI: <tel:+14251234567>

P-Associated-URI: <sip:+14251234567@one.att.net>

Service-Route: <sip:scscf.anyims.test.3gpp.com;lr>

Path: <sip:[fd29:cc43:7fb9:2:20c:29ff:fe66:b4c7];lr>

Content-Length: 0

3.数据传递及应答

3.1小数据（<1300)传递及响应

3.2大数据据（>1300)传递及响应

 3.3.被叫注册应答

4.场景2数据传递端口信息

Transmission Control Protocol, (A) Src Port: 50000 , (B) Dst Port: 55062 , Seq: 2264924161, Ack: 354, Len: 312

REGISTER sip:one.att.net SIP/2.0

Via: SIP/2.0/TCP [3000::2:5547:21cb:7edf:9962]:(C)50001;

       branch=z9hG4bK44ccabd6a7f33104360e9ae78ce1ac0d;rport

Max-Forwards: 70

Contact: <sip:310410123456789@[3000::2:5547:21cb:7edf:9962]:(D)50001;(E) transport=tcp>;

            +g.3gpp.smsip;

            +g.3gpp.icsi-ref="urn%3Aurn-7%3A3gpp-service.ims.icsi.mmtel";

            +sip.instance="<urn:gsma:imei:00440224-264925-0>"

To: <sip:310410123456789@one.att.net>

From: <sip:310410123456789@one.att.net>;tag=4887461765a4b2fc-d90ef734.0

Call-ID: 54df046e-10604c38-9f947b79@3000::2:5547:21cb:7edf:9962

CSeq: 2 REGISTER

Expires: 600000

Allow: INVITE, ACK, CANCEL, OPTIONS, BYE, REFER, NOTIFY, MESSAGE, SUBSCRIBE, INFO

User-Agent: IM-client/OMA1.0 TEST-IMS

Authorization: Digest username="310410123456789@private.att.net", realm="one.att.net",

nonce="1XcMbTY+MMNkpAePG/jtOm4yOzbFNdVV1XYObjNi45E=", uri="sip:one.att.net", response="7a87c22410c409ffef55ea37b41bfe4c",

algorithm=AKAv1-MD5,

cnonce="b4972c8ee817300a7ff36ed1cbd59be", opaque="09e88aef2....", qop=auth, nc=00000001

Security-Verify: ipsec-3gpp; ealg=null; alg=hmac-sha-1-96; spi-c=98765431; spi-s=87654321;

(F)port-c=55063;

(G)port-s=55062;

q=0.9,ipsec-3gpp; ealg=null; alg=hmac-md5-96; spi-c=98765431; spi-s=87654321;

(H)port-c=55063;

(I)port-s=55062;

q=0.7

P-Access-Network-Info: 3GPP-E-UTRAN-FDD; utran-cell-id-3gpp=31041000040000004

Supported: sec-agree, path

Proxy-Require: sec-agree

Security-Client: ipsec-3gpp; ealg=aes-cbc;

alg=hmac-sha-1-96; spi-c=41064354; spi-s=34933966;

(J)port-c=50000;

(K)port-s=50001;

prot=esp; mod=trans, ipsec-3gpp;

ealg=aes-cbc; alg=hmac-md5-96; spi-c=41064354; spi-s=34933966;

(L)port-c=50000;

(M)port-s=50001;

prot=esp; mod=trans, ipsec-3gpp; ealg=des-ede3-cbc;

alg=hmac-sha-1-96; spi-c=41064354; spi-s=34933966;

(N)port-c=50000;

(O)port-s=50001;

prot=esp; mod=trans, ipsec-3gpp; ealg=des-ede3-cbc; alg=hmac-md5-96;

spi-c=41064354; spi-s=34933966;

(P)port-c=50000;

(Q)port-s=50001;

prot=esp; mod=trans, ipsec-3gpp;

ealg=null; alg=hmac-sha-1-96; spi-c=41064354; spi-s=34933966;

(R)port-c=50000;

(S)port-s=50001;

prot=esp; mod=trans, ipsec-3gpp; ealg=null; alg=hmac-md5-96;

spi-c=41064354; spi-s=34933966;

(T)port-c=50000;

(U)port-s=50001;

prot=esp; mod=trans

Require: sec-agree

Content-Length: 0

(1)Transmission Control Protocol, (2) Src Port: 55063, (3) Dst Port: 50001, Seq: 1302, Ack: 1, Len: 341

INVITE sip:310410123456789@[3000::2:5547:21cb:7edf:9962]:(4)50001;(5)transport=tcp SIP/2.0

Via: SIP/2.0/TCP [fd29:cc43:7fb9:2:20c:29ff:fe66:b4c7]:(6)55062; branch=z9hG4bK62b4a2938807

Via: SIP/2.0/TCP scscf.anyims.test.3gpp.com; branch=z9hG4bK74eddae782b9

Max-Forwards: 69

To: <tel:+14251234567>

From: <sip:+18472733800@one.att.net;user=phone>; tag=ATL2604_06f4d629ece8

Call-ID: 551fe04688e4

CSeq: 1 INVITE

Via: SIP/2.0/TCP caller.3gpp.org:6543;branch=z9hG4bK87ee715641bd

Record-Route: <sip:scscf.anyims.test.3gpp.com;lr>

Record-Route: <sip:[fd29:cc43:7fb9:2:20c:29ff:fe66:b4c7]:(7)55062;lr>

Supported: 100rel,precondition

Allow: INVITE,ACK,CANCEL,BYE,UPDATE,PRACK,MESSAGE,REFER,NOTIFY

P-Asserted-Identity: <sip:+18472733800@one.att.net;user=phone>

P-Called-Party-ID: <tel:+14251234567>

Contact: <sip:+18472733800@[3000:0:0:2::1]:(8)5160>;

+g.3gpp.icsi-ref="urn%3Aurn-7%3A3gpp-service.ims.icsi.mmtel";video

P-Asserted-Service: urn:urn-7:3gpp-service.ims.icsi.mmtel

Accept-Contact: *;+g.3gpp.icsi-ref="urn%3Aurn-7%3A3gpp-service.ims.icsi.mmtel";video

Accept: application/sdp, application/3gpp-ims+xml

Content-Length: 486

Content-Type: application/sdp

原文来自：http://www.sharetechnote.com

整理：kangguoying20201009

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