diff --git a/packages/acn/src/enums.ts b/packages/acn/src/enums.ts
new file mode 100644
index 0000000..584f966
--- /dev/null
+++ b/packages/acn/src/enums.ts
@@ -0,0 +1,45 @@
+export enum Protocol {
+  SDT = 1,
+}
+
+export enum SDTVector {
+  REL_WRAP = 1,
+  UNREL_WRAP,
+  CHANNEL_PARAMS,
+  JOIN,
+  JOIN_REFUSE,
+  JOIN_ACCEPT,
+  LEAVE,
+  LEAVING,
+  CONNECT,
+  CONNECT_ACCEPT,
+  CONNECT_REFUSE,
+  DISCONNECT,
+  DISCONNECTING,
+  ACK,
+  NAK,
+  GET_SESSIONS,
+  SESSIONS,
+}
+
+export enum TransportLayerAddressType {
+  SDT_ADDR_NULL = 0,
+  SDT_ADDR_IPV4,
+  SDT_ADDR_IPV6,
+}
+
+export enum SDTReasonCode {
+  NONSPECIFIC = 1,
+  ILLEGAL_PARAMETERS,
+  LOW_RESOURCES,
+  ALREADY_MEMBER,
+  BAD_ADDRESS_TYPE,
+  NO_RECIPROCAL_CHANNEL,
+  CHANNEL_EXPIRED,
+  LOST_SEQUENCE,
+  SATURATED,
+  TRANSPORT_ADDRESS_CHANGING,
+  ASKED_TO_LEAVE,
+  NO_RECIPIENT,
+  ONLY_UNICAST_SUPPORTED,
+}
diff --git a/packages/acn/src/index.ts b/packages/acn/src/index.ts
index 6d508cd..a64b562 100644
--- a/packages/acn/src/index.ts
+++ b/packages/acn/src/index.ts
@@ -1,2 +1,2 @@
-export * from './models';
+export * from './types';
 export * from './udp';
diff --git a/packages/acn/src/pdu/rlp.ts b/packages/acn/src/pdu/rlp.ts
index 4e0b569..bf5c45e 100644
--- a/packages/acn/src/pdu/rlp.ts
+++ b/packages/acn/src/pdu/rlp.ts
@@ -1,5 +1,6 @@
 import pdu from '.';
-import { Protocols, RootLayerPDU, SessionDataTransportPDU } from '../models';
+import { Protocol } from '../enums';
+import { RootLayerPDU, SessionDataTransportPDU } from '../types';
 import { toHex } from '../utils';
 
 function decode(bytes: Uint8Array): RootLayerPDU {
@@ -52,8 +53,10 @@ function decode(bytes: Uint8Array): RootLayerPDU {
   const dataLength = length - (1 + 1 + (lengthFlag ? 1 : 0) + 4 + 16);
   let data: SessionDataTransportPDU | Uint8Array = bytes.subarray(dataOffset, dataOffset + dataLength);
 
-  if (vector === Protocols.SDT) {
+  if (vector === Protocol.SDT) {
     data = pdu.sdt.decode(data);
+  } else {
+    console.error(`unhandled protocol in RLP: ${vector}`)
   }
 
   return {
diff --git a/packages/acn/src/pdu/sdt.ts b/packages/acn/src/pdu/sdt.ts
index 6b0c61d..3e6e8c4 100644
--- a/packages/acn/src/pdu/sdt.ts
+++ b/packages/acn/src/pdu/sdt.ts
@@ -1,5 +1,5 @@
+import { Protocol, SDTVector } from '../enums';
 import {
-  Protocols,
   SDTAckData,
   SDTConnectAcceptData,
   SDTConnectData,
@@ -14,9 +14,8 @@ import {
   SDTNakData,
   SDTWrapperData,
   SessionDataTransportPDU,
-  SessionDataTransportVectors,
   TransportLayerAddress,
-} from '../models';
+} from '../types';
 import { toHex } from '../utils';
 
 // TODO(jwetzell): work out flag inheritance, will need previous PDU
@@ -115,7 +114,7 @@ function decodeClientBlock(bytes: Uint8Array) {
   const dataLength = length - (1 + 1 + (lengthFlag ? 1 : 0) + 2 + 6);
   let data: SessionDataTransportPDU | Uint8Array = bytes.subarray(dataOffset, dataOffset + dataLength);
 
-  if (clientProtocol === Protocols.SDT) {
+  if (clientProtocol === Protocol.SDT) {
     data = decode(data);
   } else {
     console.error(`SDT client block contains unknown protocol: ${clientProtocol}`);
@@ -129,7 +128,7 @@ function decodeClientBlock(bytes: Uint8Array) {
 }
 
 function decodeData(
-  vector: SessionDataTransportVectors,
+  vector: SDTVector,
   bytes: Uint8Array
 ):
   | SDTJoinData
@@ -148,7 +147,7 @@ function decodeData(
   | Uint8Array {
   const view = new DataView(bytes.buffer, bytes.byteOffset, bytes.byteLength);
   switch (vector) {
-    case SessionDataTransportVectors.JOIN: {
+    case SDTVector.JOIN: {
       const destinationAddress: TransportLayerAddress = {
         type: view.getUint8(30),
       };
@@ -180,7 +179,7 @@ function decodeData(
       };
       return joinData;
     }
-    case SessionDataTransportVectors.JOIN_ACCEPT: {
+    case SDTVector.JOIN_ACCEPT: {
       const joinData = {
         leaderComponentID: toHex(bytes.subarray(0, 16)),
         channelNumber: view.getUint16(16),
@@ -190,7 +189,7 @@ function decodeData(
       };
       return joinData;
     }
-    case SessionDataTransportVectors.JOIN_REFUSE: {
+    case SDTVector.JOIN_REFUSE: {
       const joinData = {
         leaderComponentID: toHex(bytes.subarray(0, 16)),
         channelNumber: view.getUint16(16),
@@ -201,8 +200,8 @@ function decodeData(
 
       return joinData;
     }
-    case SessionDataTransportVectors.REL_WRAP:
-    case SessionDataTransportVectors.UNREL_WRAP: {
+    case SDTVector.REL_WRAP:
+    case SDTVector.UNREL_WRAP: {
       const wrapperData: SDTWrapperData = {
         channelNumber: view.getUint16(0),
         totalSequenceNumber: view.getUint32(2),
@@ -216,12 +215,12 @@ function decodeData(
 
       return wrapperData;
     }
-    case SessionDataTransportVectors.ACK: {
+    case SDTVector.ACK: {
       return {
         reliableSequenceNumber: view.getUint32(0),
       };
     }
-    case SessionDataTransportVectors.LEAVING: {
+    case SDTVector.LEAVING: {
       return {
         leaderComponentID: toHex(bytes.subarray(0, 16)),
         channelNumber: view.getUint16(16),
@@ -230,12 +229,12 @@ function decodeData(
         reasonCode: view.getUint8(24),
       };
     }
-    case SessionDataTransportVectors.GET_SESSIONS: {
+    case SDTVector.GET_SESSIONS: {
       return {
         componentID: toHex(bytes.subarray(0, 16)),
       };
     }
-    case SessionDataTransportVectors.NAK: {
+    case SDTVector.NAK: {
       return {
         leaderComponentID: toHex(bytes.subarray(0, 16)),
         channelNumber: view.getUint16(16),
@@ -245,20 +244,20 @@ function decodeData(
         lastMissedSequence: view.getUint32(28),
       };
     }
-    case SessionDataTransportVectors.DISCONNECT:
-    case SessionDataTransportVectors.CONNECT:
-    case SessionDataTransportVectors.CONNECT_ACCEPT: {
+    case SDTVector.DISCONNECT:
+    case SDTVector.CONNECT:
+    case SDTVector.CONNECT_ACCEPT: {
       return {
         protocolID: view.getUint32(0),
       };
     }
-    case SessionDataTransportVectors.CONNECT_REFUSE: {
+    case SDTVector.CONNECT_REFUSE: {
       return {
         protocolID: view.getUint32(0),
         refuseCode: view.getUint8(4),
       };
     }
-    case SessionDataTransportVectors.DISCONNECTING: {
+    case SDTVector.DISCONNECTING: {
       return {
         protocolID: view.getUint32(0),
         reasonCode: view.getUint8(4),
diff --git a/packages/acn/src/models.ts b/packages/acn/src/types.ts
similarity index 83%
rename from packages/acn/src/models.ts
rename to packages/acn/src/types.ts
index 3c2e858..fe4eb3f 100644
--- a/packages/acn/src/models.ts
+++ b/packages/acn/src/types.ts
@@ -1,6 +1,4 @@
-export enum Protocols {
-  SDT = 1,
-}
+import { TransportLayerAddressType, SDTVector, SDTReasonCode } from './enums';
 
 export type UDPPreamble = {
   preambleSize: number;
@@ -20,32 +18,6 @@ export type RootLayerPDU = {
   data: SessionDataTransportPDU | Uint8Array;
 };
 
-export enum SessionDataTransportVectors {
-  REL_WRAP = 1,
-  UNREL_WRAP,
-  CHANNEL_PARAMS,
-  JOIN,
-  JOIN_REFUSE,
-  JOIN_ACCEPT,
-  LEAVE,
-  LEAVING,
-  CONNECT,
-  CONNECT_ACCEPT,
-  CONNECT_REFUSE,
-  DISCONNECT,
-  DISCONNECTING,
-  ACK,
-  NAK,
-  GET_SESSIONS,
-  SESSIONS,
-}
-
-export enum TransportLayerAddressTypes {
-  SDT_ADDR_NULL = 0,
-  SDT_ADDR_IPV4,
-  SDT_ADDR_IPV6,
-}
-
 export type SDTChannelParams = {
   expiry: number;
   nakOutboundFlag: number;
@@ -55,7 +27,7 @@ export type SDTChannelParams = {
 };
 
 export type TransportLayerAddress = {
-  type: TransportLayerAddressTypes;
+  type: TransportLayerAddressType;
   port?: number;
   address?: string;
 };
@@ -85,7 +57,7 @@ export type SDTJoinRefuseData = {
   channelNumber: number;
   memberID: number;
   reliableSequenceNumber: number;
-  refuseCode: number;
+  refuseCode: SDTReasonCode;
 };
 
 export type SDTLeavingData = {
@@ -93,7 +65,7 @@ export type SDTLeavingData = {
   channelNumber: number;
   memberID: number;
   reliableSequenceNumber: number;
-  reasonCode: number;
+  reasonCode: SDTReasonCode;
 };
 
 export type SDTWrapperData = {
@@ -127,13 +99,13 @@ export type SDTConnectData = {
 export type SDTConnectAcceptData = SDTConnectData;
 export type SDTConnectRefuseData = {
   protocolID: number;
-  refuseCode: number;
+  refuseCode: SDTReasonCode;
 };
 
 export type SDTDisconnectData = SDTConnectData;
 export type SDTDisconnectingData = {
   protocolID: number;
-  reasonCode: number;
+  reasonCode: SDTReasonCode;
 };
 
 export type SDTGetSessionsData = {
@@ -141,7 +113,7 @@ export type SDTGetSessionsData = {
 };
 
 export type SessionDataTransportPDU = {
-  vector: SessionDataTransportVectors;
+  vector: SDTVector;
   // TODO(jwetzell): cleanup these types
   data:
     | SDTJoinData
diff --git a/packages/acn/src/udp.ts b/packages/acn/src/udp.ts
index 8e1a8b5..0877fae 100644
--- a/packages/acn/src/udp.ts
+++ b/packages/acn/src/udp.ts
@@ -1,4 +1,4 @@
-import { ACNPacket, RootLayerPDU, UDPPreamble } from './models';
+import { ACNPacket, RootLayerPDU, UDPPreamble } from './types';
 import pdu from './pdu';
 
 // ANSI E1.17 - 2015 (R2020) EPI 17