--- a/media/webrtc/signaling/gtest/sdp_unittests.cpp
+++ b/media/webrtc/signaling/gtest/sdp_unittests.cpp
@@ -4060,16 +4060,85 @@ TEST_P(NewSdpTest, CheckAddMediaSection)
                           SdpDirectionAttribute::Direction::kSendonly,
                           14006, SdpMediaSection::kTcpTlsRtpSavpf, sdp::kIPv6,
                           "NOT:AN.IP.ADDRESS");
     ASSERT_EQ(5U, mSdp->GetMediaSectionCount())
       << "Wrong number of media sections after adding media section";
   }
 }
 
+TEST_P(NewSdpTest, CheckAddDataChannel_Draft05) {
+  // Parse any valid sdp with a media section
+  ParseSdp("v=0" CRLF
+           "o=- 4294967296 2 IN IP4 127.0.0.1" CRLF
+           "s=SIP Call" CRLF
+           "c=IN IP4 198.51.100.7" CRLF
+           "b=CT:5000" CRLF
+           "t=0 0" CRLF
+           "m=application 56436 DTLS/SCTP 5000" CRLF);
+
+  ASSERT_TRUE(!!mSdp) << "Parse failed: " << GetParseErrors();
+  ASSERT_EQ(1U, mSdp->GetMediaSectionCount());
+
+  auto& mediaSection = mSdp->GetMediaSection(0);
+  mediaSection.AddDataChannel("webrtc-datachannel", 6000, 16, 0);
+
+  ASSERT_FALSE(mediaSection.GetAttributeList().
+              HasAttribute(SdpAttribute::kMaxMessageSizeAttribute));
+  ASSERT_TRUE(mediaSection.GetAttributeList().
+              HasAttribute(SdpAttribute::kSctpmapAttribute));
+  ASSERT_TRUE(mediaSection.GetAttributeList().GetSctpmap().HasEntry("6000"));
+  ASSERT_EQ(16U, mediaSection.GetAttributeList().
+                 GetSctpmap().GetFirstEntry().streams);
+  ASSERT_EQ("webrtc-datachannel", mediaSection.GetAttributeList().
+                                  GetSctpmap().GetFirstEntry().name);
+
+  mediaSection.AddDataChannel("webrtc-datachannel", 15000, 8, 1800);
+
+  ASSERT_TRUE(mediaSection.GetAttributeList().
+              HasAttribute(SdpAttribute::kMaxMessageSizeAttribute));
+  ASSERT_EQ(1800U, mediaSection.GetAttributeList().GetMaxMessageSize());
+  ASSERT_TRUE(mediaSection.GetAttributeList().
+              HasAttribute(SdpAttribute::kSctpmapAttribute));
+  ASSERT_TRUE(mediaSection.GetAttributeList().GetSctpmap().HasEntry("15000"));
+  ASSERT_EQ(8U, mediaSection.GetAttributeList().
+                GetSctpmap().GetFirstEntry().streams);
+}
+
+TEST_P(NewSdpTest, CheckAddDataChannel) {
+  ParseSdp("v=0" CRLF
+           "o=- 4294967296 2 IN IP4 127.0.0.1" CRLF
+           "s=SIP Call" CRLF
+           "c=IN IP4 198.51.100.7" CRLF
+           "b=CT:5000" CRLF
+           "t=0 0" CRLF
+           "m=application 56436 UDP/DTLS/SCTP webrtc-datachannel" CRLF);
+
+  ASSERT_TRUE(!!mSdp) << "Parse failed: " << GetParseErrors();
+  ASSERT_EQ(1U, mSdp->GetMediaSectionCount());
+
+  auto& mediaSection = mSdp->GetMediaSection(0);
+  mediaSection.AddDataChannel("webrtc-datachannel", 6000, 16, 0);
+
+  ASSERT_FALSE(mediaSection.GetAttributeList().
+              HasAttribute(SdpAttribute::kMaxMessageSizeAttribute));
+  ASSERT_TRUE(mediaSection.GetAttributeList().
+              HasAttribute(SdpAttribute::kSctpPortAttribute));
+  ASSERT_EQ(6000U, mediaSection.GetAttributeList().GetSctpPort());
+
+  mediaSection.AddDataChannel("webrtc-datachannel", 15000, 8, 1800);
+
+  ASSERT_TRUE(mediaSection.GetAttributeList().
+              HasAttribute(SdpAttribute::kMaxMessageSizeAttribute));
+  ASSERT_EQ(1800U, mediaSection.GetAttributeList().GetMaxMessageSize());
+  ASSERT_TRUE(mediaSection.GetAttributeList().
+              HasAttribute(SdpAttribute::kSctpPortAttribute));
+  ASSERT_EQ(15000U, mediaSection.GetAttributeList().GetSctpPort());
+}
+
 TEST(NewSdpTestNoFixture, CheckAttributeTypeSerialize) {
   for (auto a = static_cast<size_t>(SdpAttribute::kFirstAttribute);
        a <= static_cast<size_t>(SdpAttribute::kLastAttribute);
        ++a) {
 
     SdpAttribute::AttributeType type =
       static_cast<SdpAttribute::AttributeType>(a);
 

--- a/media/webrtc/signaling/src/sdp/RsdparsaSdpAttributeList.cpp
+++ b/media/webrtc/signaling/src/sdp/RsdparsaSdpAttributeList.cpp
@@ -811,17 +811,17 @@ RsdparsaSdpAttributeList::LoadFlags(Rust
   if (flags.endOfCandidates) {
     SetAttribute(new SdpFlagAttribute(SdpAttribute::kEndOfCandidatesAttribute));
   }
 }
 
 void
 RsdparsaSdpAttributeList::LoadMaxMessageSize(RustAttributeList* attributeList)
 {
-  int64_t max_msg_size = sdp_get_max_msg_sizse(attributeList);
+  int64_t max_msg_size = sdp_get_max_msg_size(attributeList);
   if (max_msg_size >= 0) {
     SetAttribute(new SdpNumberAttribute(SdpAttribute::kMaxMessageSizeAttribute,
                                         static_cast<uint32_t>(max_msg_size)));
   }
 }
 
 void
 RsdparsaSdpAttributeList::LoadMid(RustAttributeList* attributeList)

--- a/media/webrtc/signaling/src/sdp/RsdparsaSdpInc.h
+++ b/media/webrtc/signaling/src/sdp/RsdparsaSdpInc.h
@@ -328,17 +328,17 @@ size_t sdp_get_rtpmap_count(const RustAt
 void sdp_get_rtpmaps(const RustAttributeList* aList, size_t listSize,
                      RustSdpAttributeRtpmap* ret);
 
 size_t sdp_get_fmtp_count(const RustAttributeList* aList);
 size_t sdp_get_fmtp(const RustAttributeList* aList, size_t listSize,
                     RustSdpAttributeFmtp* ret);
 
 int64_t sdp_get_ptime(const RustAttributeList* aList);
-int64_t sdp_get_max_msg_sizse(const RustAttributeList* aList);
+int64_t sdp_get_max_msg_size(const RustAttributeList* aList);
 int64_t sdp_get_sctp_port(const RustAttributeList* aList);
 
 RustSdpAttributeFlags sdp_get_attribute_flags(const RustAttributeList* aList);
 
 nsresult sdp_get_mid(const RustAttributeList* aList, StringView* ret);
 
 size_t sdp_get_msid_count(const RustAttributeList* aList);
 void sdp_get_msids(const RustAttributeList* aList, size_t listSize,

--- a/media/webrtc/signaling/src/sdp/rsdparsa_capi/src/attribute.rs
+++ b/media/webrtc/signaling/src/sdp/rsdparsa_capi/src/attribute.rs
@@ -435,17 +435,17 @@ pub unsafe extern "C" fn sdp_get_ptime(a
         if let SdpAttribute::Ptime(time) = *attribute {
             return time as int64_t;
         }
     }
     -1
 }
 
 #[no_mangle]
-pub unsafe extern "C" fn sdp_get_max_msg_sizse(attributes: *const Vec<SdpAttribute>) -> int64_t {
+pub unsafe extern "C" fn sdp_get_max_msg_size(attributes: *const Vec<SdpAttribute>) -> int64_t {
     for attribute in (*attributes).iter() {
         if let SdpAttribute::MaxMessageSize(max_msg_size) = *attribute {
             return max_msg_size as int64_t;
         }
     }
     -1
 }