diff --git a/doc/doxygen/lwip.Doxyfile b/doc/doxygen/lwip.Doxyfile
index a9ed15db..a484565c 100644
--- a/doc/doxygen/lwip.Doxyfile
+++ b/doc/doxygen/lwip.Doxyfile
@@ -44,7 +44,7 @@ PROJECT_NUMBER         = "lwIP 2.0.0"
 # for a project that appears at the top of each page and should give viewer a
 # quick idea about the purpose of the project. Keep the description short.
 
-PROJECT_BRIEF          =
+PROJECT_BRIEF          = Lightweight IP stack
 
 # With the PROJECT_LOGO tag one can specify a logo or an icon that is included
 # in the documentation. The maximum height of the logo should not exceed 55
diff --git a/src/api/api_lib.c b/src/api/api_lib.c
index 95f18853..ae630781 100644
--- a/src/api/api_lib.c
+++ b/src/api/api_lib.c
@@ -796,6 +796,8 @@ netconn_close(struct netconn *conn)
  * Shut down one or both sides of a TCP netconn (doesn't delete it).
  *
  * @param conn the TCP netconn to shut down
+ * @param shut_rx abort running reads
+ * @param shut_tx abort running writes
  * @return ERR_OK if the netconn was closed, any other err_t on error
  */
 err_t
diff --git a/src/apps/snmp/snmp_asn1.c b/src/apps/snmp/snmp_asn1.c
index afd48b2c..89071059 100644
--- a/src/apps/snmp/snmp_asn1.c
+++ b/src/apps/snmp/snmp_asn1.c
@@ -46,6 +46,13 @@
     return ERR_BUF; \
   }
 
+/**
+ * Encodes a TLV into a pbuf stream.
+ *
+ * @param pbuf_stream points to a pbuf stream
+ * @param tlv TLV to encode
+ * @return ERR_OK if successful, ERR_ARG if we can't (or won't) encode
+ */
 err_t
 snmp_ans1_enc_tlv(struct snmp_pbuf_stream* pbuf_stream, struct snmp_asn1_tlv* tlv)
 {
@@ -118,8 +125,7 @@ snmp_ans1_enc_tlv(struct snmp_pbuf_stream* pbuf_stream, struct snmp_asn1_tlv* tl
 /**
  * Encodes raw data (octet string, opaque) into a pbuf chained ASN1 msg.
  *
- * @param p points to output pbuf to encode raw data into
- * @param ofs points to the offset within the pbuf chain
+ * @param pbuf_stream points to a pbuf stream
  * @param raw_len raw data length
  * @param raw points raw data
  * @return ERR_OK if successful, ERR_ARG if we can't (or won't) encode
@@ -135,8 +141,7 @@ snmp_asn1_enc_raw(struct snmp_pbuf_stream* pbuf_stream, const u8_t *raw, u16_t r
 /**
  * Encodes u32_t (counter, gauge, timeticks) into a pbuf chained ASN1 msg.
  *
- * @param p points to output pbuf to encode value into
- * @param ofs points to the offset within the pbuf chain
+ * @param pbuf_stream points to a pbuf stream
  * @param octets_needed encoding length (from snmp_asn1_enc_u32t_cnt())
  * @param value is the host order u32_t value to be encoded
  * @return ERR_OK if successful, ERR_ARG if we can't (or won't) encode
@@ -169,8 +174,7 @@ snmp_asn1_enc_u32t(struct snmp_pbuf_stream* pbuf_stream, u16_t octets_needed, u3
 /**
  * Encodes u64_t (counter64) into a pbuf chained ASN1 msg.
  *
- * @param p points to output pbuf to encode value into
- * @param ofs points to the offset within the pbuf chain
+ * @param pbuf_stream points to a pbuf stream
  * @param octets_needed encoding length (from snmp_asn1_enc_u32t_cnt())
  * @param value is the host order u32_t value to be encoded
  * @return ERR_OK if successful, ERR_ARG if we can't (or won't) encode
@@ -211,8 +215,7 @@ snmp_asn1_enc_u64t(struct snmp_pbuf_stream* pbuf_stream, u16_t octets_needed, co
 /**
  * Encodes s32_t integer into a pbuf chained ASN1 msg.
  *
- * @param p points to output pbuf to encode value into
- * @param ofs points to the offset within the pbuf chain
+ * @param pbuf_stream points to a pbuf stream
  * @param octets_needed encoding length (from snmp_asn1_enc_s32t_cnt())
  * @param value is the host order s32_t value to be encoded
  * @return ERR_OK if successful, ERR_ARG if we can't (or won't) encode
@@ -237,10 +240,9 @@ snmp_asn1_enc_s32t(struct snmp_pbuf_stream* pbuf_stream, u16_t octets_needed, s3
 /**
  * Encodes object identifier into a pbuf chained ASN1 msg.
  *
- * @param p points to output pbuf to encode oid into
- * @param ofs points to the offset within the pbuf chain
- * @param ident_len object identifier array length
- * @param ident points to object identifier array
+ * @param pbuf_stream points to a pbuf stream
+ * @param oid points to object identifier array
+ * @param oid_len object identifier array length
  * @return ERR_OK if successful, ERR_ARG if we can't (or won't) encode
  */
 err_t
@@ -382,8 +384,8 @@ snmp_asn1_enc_s32t_cnt(s32_t value, u16_t *octets_needed)
 /**
  * Returns octet count for an object identifier.
  *
- * @param ident_len object identifier array length
- * @param ident points to object identifier array
+ * @param oid points to object identifier array
+ * @param oid_len object identifier array length
  * @param octets_needed points to the return value
  */
 void
@@ -412,6 +414,13 @@ snmp_asn1_enc_oid_cnt(const u32_t *oid, u16_t oid_len, u16_t *octets_needed)
   }
 }
 
+/**
+ * Decodes a TLV from a pbuf stream.
+ *
+ * @param pbuf_stream points to a pbuf stream
+ * @param tlv returns decoded TLV
+ * @return ERR_OK if successful, ERR_VAL if we can't decode
+ */
 err_t
 snmp_asn1_dec_tlv(struct snmp_pbuf_stream* pbuf_stream, struct snmp_asn1_tlv* tlv)
 {
@@ -465,8 +474,7 @@ snmp_asn1_dec_tlv(struct snmp_pbuf_stream* pbuf_stream, struct snmp_asn1_tlv* tl
 /**
  * Decodes positive integer (counter, gauge, timeticks) into u32_t.
  *
- * @param p points to a pbuf holding an ASN1 coded integer
- * @param ofs points to the offset within the pbuf chain of the ASN1 coded integer
+ * @param pbuf_stream points to a pbuf stream
  * @param len length of the coded integer field
  * @param value return host order integer
  * @return ERR_OK if successful, ERR_ARG if we can't (or won't) decode
@@ -507,8 +515,7 @@ snmp_asn1_dec_u32t(struct snmp_pbuf_stream *pbuf_stream, u16_t len, u32_t *value
 /**
  * Decodes large positive integer (counter64) into 2x u32_t.
  *
- * @param p points to a pbuf holding an ASN1 coded integer
- * @param ofs points to the offset within the pbuf chain of the ASN1 coded integer
+ * @param pbuf_stream points to a pbuf stream
  * @param len length of the coded integer field
  * @param value return host order integer
  * @return ERR_OK if successful, ERR_ARG if we can't (or won't) decode
@@ -563,8 +570,7 @@ snmp_asn1_dec_u64t(struct snmp_pbuf_stream *pbuf_stream, u16_t len, u32_t *value
 /**
  * Decodes integer into s32_t.
  *
- * @param p points to a pbuf holding an ASN1 coded integer
- * @param ofs points to the offset within the pbuf chain of the ASN1 coded integer
+ * @param pbuf_stream points to a pbuf stream
  * @param len length of the coded integer field
  * @param value return host order integer
  * @return ERR_OK if successful, ERR_ARG if we can't (or won't) decode