diff --git a/gb28181-sip/src/main/java/cn/skcks/docking/gb28181/sdp/GB28181Description.java b/gb28181-sip/src/main/java/cn/skcks/docking/gb28181/sdp/GB28181Description.java
index 350425e..4908f49 100644
--- a/gb28181-sip/src/main/java/cn/skcks/docking/gb28181/sdp/GB28181Description.java
+++ b/gb28181-sip/src/main/java/cn/skcks/docking/gb28181/sdp/GB28181Description.java
@@ -1,5 +1,6 @@
 package cn.skcks.docking.gb28181.sdp;
 
+import cn.skcks.docking.gb28181.sdp.field.ssrc.SsrcField;
 import gov.nist.javax.sdp.SessionDescriptionImpl;
 import lombok.Getter;
 import lombok.Setter;
@@ -33,7 +34,6 @@ public class GB28181Description extends SessionDescriptionImpl implements Sessio
     public String toString() {
         StringBuilder sb = new StringBuilder(super.toString());
         sb.append(getSsrcField() == null ? "" : getSsrcField().toString());
-        // return "+";
         return sb.toString();
     }
 }
diff --git a/gb28181-sip/src/main/java/cn/skcks/docking/gb28181/sdp/Gb28181Sdp.java b/gb28181-sip/src/main/java/cn/skcks/docking/gb28181/sdp/Gb28181Sdp.java
deleted file mode 100644
index 48a7d3f..0000000
--- a/gb28181-sip/src/main/java/cn/skcks/docking/gb28181/sdp/Gb28181Sdp.java
+++ /dev/null
@@ -1,14 +0,0 @@
-package cn.skcks.docking.gb28181.sdp;
-
-import lombok.Builder;
-import lombok.Data;
-
-import javax.sdp.SessionDescription;
-
-@Builder
-@Data
-public class Gb28181Sdp {
-    private SessionDescription baseSdb;
-    private String ssrc;
-    private String mediaDescription;
-}
diff --git a/gb28181-sip/src/main/java/cn/skcks/docking/gb28181/sdp/SsrcField.java b/gb28181-sip/src/main/java/cn/skcks/docking/gb28181/sdp/field/ssrc/SsrcField.java
similarity index 92%
rename from gb28181-sip/src/main/java/cn/skcks/docking/gb28181/sdp/SsrcField.java
rename to gb28181-sip/src/main/java/cn/skcks/docking/gb28181/sdp/field/ssrc/SsrcField.java
index c9045dc..93a1203 100644
--- a/gb28181-sip/src/main/java/cn/skcks/docking/gb28181/sdp/SsrcField.java
+++ b/gb28181-sip/src/main/java/cn/skcks/docking/gb28181/sdp/field/ssrc/SsrcField.java
@@ -1,4 +1,4 @@
-package cn.skcks.docking.gb28181.sdp;
+package cn.skcks.docking.gb28181.sdp.field.ssrc;
 
 import gov.nist.core.Separators;
 import gov.nist.javax.sdp.fields.SDPField;
diff --git a/gb28181-sip/src/main/java/cn/skcks/docking/gb28181/sdp/SsrcFieldParser.java b/gb28181-sip/src/main/java/cn/skcks/docking/gb28181/sdp/field/ssrc/parser/SsrcFieldParser.java
similarity index 88%
rename from gb28181-sip/src/main/java/cn/skcks/docking/gb28181/sdp/SsrcFieldParser.java
rename to gb28181-sip/src/main/java/cn/skcks/docking/gb28181/sdp/field/ssrc/parser/SsrcFieldParser.java
index f6134c9..16c0806 100644
--- a/gb28181-sip/src/main/java/cn/skcks/docking/gb28181/sdp/SsrcFieldParser.java
+++ b/gb28181-sip/src/main/java/cn/skcks/docking/gb28181/sdp/field/ssrc/parser/SsrcFieldParser.java
@@ -1,5 +1,6 @@
-package cn.skcks.docking.gb28181.sdp;
+package cn.skcks.docking.gb28181.sdp.field.ssrc.parser;
 
+import cn.skcks.docking.gb28181.sdp.field.ssrc.SsrcField;
 import gov.nist.javax.sdp.fields.SDPField;
 import gov.nist.javax.sdp.parser.Lexer;
 import gov.nist.javax.sdp.parser.SDPParser;
diff --git a/gb28181-sip/src/main/java/cn/skcks/docking/gb28181/sdp/GB28181DescriptionParser.java b/gb28181-sip/src/main/java/cn/skcks/docking/gb28181/sdp/parser/GB28181DescriptionParser.java
similarity index 95%
rename from gb28181-sip/src/main/java/cn/skcks/docking/gb28181/sdp/GB28181DescriptionParser.java
rename to gb28181-sip/src/main/java/cn/skcks/docking/gb28181/sdp/parser/GB28181DescriptionParser.java
index d384e2e..78709b8 100644
--- a/gb28181-sip/src/main/java/cn/skcks/docking/gb28181/sdp/GB28181DescriptionParser.java
+++ b/gb28181-sip/src/main/java/cn/skcks/docking/gb28181/sdp/parser/GB28181DescriptionParser.java
@@ -1,7 +1,8 @@
-package cn.skcks.docking.gb28181.sdp;
+package cn.skcks.docking.gb28181.sdp.parser;
 
+import cn.skcks.docking.gb28181.sdp.GB28181Description;
+import cn.skcks.docking.gb28181.sdp.field.ssrc.SsrcField;
 import gov.nist.core.ParserCore;
-import gov.nist.javax.sdp.SessionDescriptionImpl;
 import gov.nist.javax.sdp.fields.SDPField;
 import gov.nist.javax.sdp.parser.Lexer;
 import gov.nist.javax.sdp.parser.SDPParser;
diff --git a/gb28181-sip/src/main/java/cn/skcks/docking/gb28181/sdp/GB28181DescriptionParserFactory.java b/gb28181-sip/src/main/java/cn/skcks/docking/gb28181/sdp/parser/GB28181DescriptionParserFactory.java
similarity index 81%
rename from gb28181-sip/src/main/java/cn/skcks/docking/gb28181/sdp/GB28181DescriptionParserFactory.java
rename to gb28181-sip/src/main/java/cn/skcks/docking/gb28181/sdp/parser/GB28181DescriptionParserFactory.java
index 70c85c6..1ef01fe 100644
--- a/gb28181-sip/src/main/java/cn/skcks/docking/gb28181/sdp/GB28181DescriptionParserFactory.java
+++ b/gb28181-sip/src/main/java/cn/skcks/docking/gb28181/sdp/parser/GB28181DescriptionParserFactory.java
@@ -1,5 +1,6 @@
-package cn.skcks.docking.gb28181.sdp;
+package cn.skcks.docking.gb28181.sdp.parser;
 
+import cn.skcks.docking.gb28181.sdp.field.ssrc.parser.SsrcFieldParser;
 import gov.nist.javax.sdp.parser.Lexer;
 import gov.nist.javax.sdp.parser.ParserFactory;
 import gov.nist.javax.sdp.parser.SDPParser;
diff --git a/gb28181-sip/src/test/java/cn/skcks/docking/gb28181/sdp/SdpTest.java b/gb28181-sip/src/test/java/cn/skcks/docking/gb28181/sdp/SdpTest.java
index 9ebd8e1..ddbbccd 100644
--- a/gb28181-sip/src/test/java/cn/skcks/docking/gb28181/sdp/SdpTest.java
+++ b/gb28181-sip/src/test/java/cn/skcks/docking/gb28181/sdp/SdpTest.java
@@ -1,5 +1,7 @@
 package cn.skcks.docking.gb28181.sdp;
 
+import cn.skcks.docking.gb28181.sdp.field.ssrc.SsrcField;
+import cn.skcks.docking.gb28181.sdp.parser.GB28181DescriptionParser;
 import gov.nist.javax.sdp.SessionDescriptionImpl;
 import gov.nist.javax.sdp.fields.TimeField;
 import lombok.SneakyThrows;