diff --git a/beacon-chain/p2p/encoder/ssz.go b/beacon-chain/p2p/encoder/ssz.go
index df53b4a9f..ac118df5f 100644
--- a/beacon-chain/p2p/encoder/ssz.go
+++ b/beacon-chain/p2p/encoder/ssz.go
@@ -16,7 +16,8 @@ import (
 var _ NetworkEncoding = (*SszNetworkEncoder)(nil)
 
 // MaxGossipSize allowed for gossip messages.
-var MaxGossipSize = params.BeaconNetworkConfig().GossipMaxSize // 1 Mib
+var MaxGossipSize = params.BeaconNetworkConfig().GossipMaxSize // 1 Mib.
+var MaxChunkSize = params.BeaconNetworkConfig().MaxChunkSize   // 1 Mib.
 
 // This pool defines the sync pool for our buffered snappy writers, so that they
 // can be constantly reused.
@@ -59,11 +60,11 @@ func (_ SszNetworkEncoder) EncodeWithMaxLength(w io.Writer, msg fastssz.Marshale
 	if err != nil {
 		return 0, err
 	}
-	if uint64(len(b)) > params.BeaconNetworkConfig().MaxChunkSize {
+	if uint64(len(b)) > MaxChunkSize {
 		return 0, fmt.Errorf(
 			"size of encoded message is %d which is larger than the provided max limit of %d",
 			len(b),
-			params.BeaconNetworkConfig().MaxChunkSize,
+			MaxChunkSize,
 		)
 	}
 	// write varint first
@@ -110,11 +111,11 @@ func (e SszNetworkEncoder) DecodeWithMaxLength(r io.Reader, to fastssz.Unmarshal
 	if err != nil {
 		return err
 	}
-	if msgLen > params.BeaconNetworkConfig().MaxChunkSize {
+	if msgLen > MaxChunkSize {
 		return fmt.Errorf(
 			"remaining bytes %d goes over the provided max limit of %d",
 			msgLen,
-			params.BeaconNetworkConfig().MaxChunkSize,
+			MaxChunkSize,
 		)
 	}
 	msgMax, err := e.MaxLength(msgLen)
@@ -199,3 +200,13 @@ func newBufferedWriter(w io.Writer) *snappy.Writer {
 	bufW.Reset(w)
 	return bufW
 }
+
+// SetMaxGossipSizeForBellatrix sets the MaxGossipSize to 10Mb.
+func SetMaxGossipSizeForBellatrix() {
+	MaxGossipSize = params.BeaconNetworkConfig().GossipMaxSizeBellatrix
+}
+
+// SetMaxChunkSizeForBellatrix sets the MaxChunkSize to 10Mb.
+func SetMaxChunkSizeForBellatrix() {
+	MaxChunkSize = params.BeaconNetworkConfig().MaxChunkSizeBellatrix
+}
diff --git a/beacon-chain/p2p/encoder/ssz_test.go b/beacon-chain/p2p/encoder/ssz_test.go
index 2b7f38bdc..620e66315 100644
--- a/beacon-chain/p2p/encoder/ssz_test.go
+++ b/beacon-chain/p2p/encoder/ssz_test.go
@@ -77,10 +77,10 @@ func TestSszNetworkEncoder_EncodeWithMaxLength(t *testing.T) {
 	e := &encoder.SszNetworkEncoder{}
 	params.SetupTestConfigCleanup(t)
 	c := params.BeaconNetworkConfig()
-	c.MaxChunkSize = uint64(5)
+	encoder.MaxChunkSize = uint64(5)
 	params.OverrideBeaconNetworkConfig(c)
 	_, err := e.EncodeWithMaxLength(buf, msg)
-	wanted := fmt.Sprintf("which is larger than the provided max limit of %d", params.BeaconNetworkConfig().MaxChunkSize)
+	wanted := fmt.Sprintf("which is larger than the provided max limit of %d", encoder.MaxChunkSize)
 	assert.ErrorContains(t, wanted, err)
 }
 
@@ -95,7 +95,7 @@ func TestSszNetworkEncoder_DecodeWithMaxLength(t *testing.T) {
 	params.SetupTestConfigCleanup(t)
 	c := params.BeaconNetworkConfig()
 	maxChunkSize := uint64(5)
-	c.MaxChunkSize = maxChunkSize
+	encoder.MaxChunkSize = maxChunkSize
 	params.OverrideBeaconNetworkConfig(c)
 	_, err := e.EncodeGossip(buf, msg)
 	require.NoError(t, err)
@@ -113,7 +113,7 @@ func TestSszNetworkEncoder_DecodeWithMultipleFrames(t *testing.T) {
 	c := params.BeaconNetworkConfig()
 	// 4 * 1 Mib
 	maxChunkSize := uint64(1 << 22)
-	c.MaxChunkSize = maxChunkSize
+	encoder.MaxChunkSize = maxChunkSize
 	params.OverrideBeaconNetworkConfig(c)
 	_, err := e.EncodeWithMaxLength(buf, st.InnerStateUnsafe().(*ethpb.BeaconState))
 	require.NoError(t, err)
diff --git a/beacon-chain/p2p/fork_watcher.go b/beacon-chain/p2p/fork_watcher.go
index d7f3c3d31..da762e869 100644
--- a/beacon-chain/p2p/fork_watcher.go
+++ b/beacon-chain/p2p/fork_watcher.go
@@ -1,6 +1,7 @@
 package p2p
 
 import (
+	"github.com/prysmaticlabs/prysm/beacon-chain/p2p/encoder"
 	"github.com/prysmaticlabs/prysm/config/params"
 	"github.com/prysmaticlabs/prysm/time/slots"
 )
@@ -14,7 +15,8 @@ func (s *Service) forkWatcher() {
 		select {
 		case currSlot := <-slotTicker.C():
 			currEpoch := slots.ToEpoch(currSlot)
-			if currEpoch == params.BeaconConfig().AltairForkEpoch {
+			if currEpoch == params.BeaconConfig().AltairForkEpoch ||
+				currEpoch == params.BeaconConfig().BellatrixForkEpoch {
 				// If we are in the fork epoch, we update our enr with
 				// the updated fork digest. These repeatedly does
 				// this over the epoch, which might be slightly wasteful
@@ -23,6 +25,12 @@ func (s *Service) forkWatcher() {
 				if err != nil {
 					log.WithError(err).Error("Could not add fork entry")
 				}
+
+				// from Bellatrix Epoch, the MaxGossipSize and the MaxChunkSize is changed to 10Mb.
+				if currEpoch == params.BeaconConfig().BellatrixForkEpoch {
+					encoder.SetMaxGossipSizeForBellatrix()
+					encoder.SetMaxChunkSizeForBellatrix()
+				}
 			}
 		case <-s.ctx.Done():
 			log.Debug("Context closed, exiting goroutine")
diff --git a/beacon-chain/p2p/gossip_topic_mappings.go b/beacon-chain/p2p/gossip_topic_mappings.go
index 68115941d..c74e5a8fa 100644
--- a/beacon-chain/p2p/gossip_topic_mappings.go
+++ b/beacon-chain/p2p/gossip_topic_mappings.go
@@ -25,8 +25,13 @@ var gossipTopicMappings = map[string]proto.Message{
 // GossipTopicMappings is a function to return the assigned data type
 // versioned by epoch.
 func GossipTopicMappings(topic string, epoch types.Epoch) proto.Message {
-	if topic == BlockSubnetTopicFormat && epoch >= params.BeaconConfig().AltairForkEpoch {
-		return &ethpb.SignedBeaconBlockAltair{}
+	if topic == BlockSubnetTopicFormat {
+		if epoch >= params.BeaconConfig().BellatrixForkEpoch {
+			return &ethpb.SignedBeaconBlockMerge{}
+		}
+		if epoch >= params.BeaconConfig().AltairForkEpoch {
+			return &ethpb.SignedBeaconBlockAltair{}
+		}
 	}
 	return gossipTopicMappings[topic]
 }
@@ -51,4 +56,5 @@ func init() {
 	}
 	// Specially handle Altair Objects.
 	GossipTypeMapping[reflect.TypeOf(&ethpb.SignedBeaconBlockAltair{})] = BlockSubnetTopicFormat
+	GossipTypeMapping[reflect.TypeOf(&ethpb.SignedBeaconBlockMerge{})] = BlockSubnetTopicFormat
 }
diff --git a/beacon-chain/p2p/gossip_topic_mappings_test.go b/beacon-chain/p2p/gossip_topic_mappings_test.go
index 285676e8f..5d85de21d 100644
--- a/beacon-chain/p2p/gossip_topic_mappings_test.go
+++ b/beacon-chain/p2p/gossip_topic_mappings_test.go
@@ -24,18 +24,28 @@ func TestMappingHasNoDuplicates(t *testing.T) {
 func TestGossipTopicMappings_CorrectBlockType(t *testing.T) {
 	params.SetupTestConfigCleanup(t)
 	bCfg := params.BeaconConfig()
-	forkEpoch := eth2types.Epoch(100)
-	bCfg.AltairForkEpoch = forkEpoch
+	altairForkEpoch := eth2types.Epoch(100)
+	BellatrixForkEpoch := eth2types.Epoch(200)
+
+	bCfg.AltairForkEpoch = altairForkEpoch
+	bCfg.BellatrixForkEpoch = BellatrixForkEpoch
 	bCfg.ForkVersionSchedule[bytesutil.ToBytes4(bCfg.AltairForkVersion)] = eth2types.Epoch(100)
+	bCfg.ForkVersionSchedule[bytesutil.ToBytes4(bCfg.BellatrixForkVersion)] = eth2types.Epoch(200)
 	params.OverrideBeaconConfig(bCfg)
 
-	// Before Fork
+	// Phase 0
 	pMessage := GossipTopicMappings(BlockSubnetTopicFormat, 0)
 	_, ok := pMessage.(*ethpb.SignedBeaconBlock)
 	assert.Equal(t, true, ok)
 
-	// After Fork
-	pMessage = GossipTopicMappings(BlockSubnetTopicFormat, forkEpoch)
+	// Altair Fork
+	pMessage = GossipTopicMappings(BlockSubnetTopicFormat, altairForkEpoch)
 	_, ok = pMessage.(*ethpb.SignedBeaconBlockAltair)
 	assert.Equal(t, true, ok)
+
+	// Bellatrix Fork
+	pMessage = GossipTopicMappings(BlockSubnetTopicFormat, BellatrixForkEpoch)
+	_, ok = pMessage.(*ethpb.SignedBeaconBlockMerge)
+	assert.Equal(t, true, ok)
+
 }
diff --git a/beacon-chain/p2p/message_id.go b/beacon-chain/p2p/message_id.go
index b13853ff2..34efd104b 100644
--- a/beacon-chain/p2p/message_id.go
+++ b/beacon-chain/p2p/message_id.go
@@ -2,6 +2,7 @@ package p2p
 
 import (
 	pubsub_pb "github.com/libp2p/go-libp2p-pubsub/pb"
+	types "github.com/prysmaticlabs/eth2-types"
 	"github.com/prysmaticlabs/prysm/beacon-chain/p2p/encoder"
 	"github.com/prysmaticlabs/prysm/config/params"
 	"github.com/prysmaticlabs/prysm/crypto/hash"
@@ -45,7 +46,7 @@ func MsgID(genesisValidatorsRoot []byte, pmsg *pubsub_pb.Message) string {
 		return string(msg)
 	}
 	if fEpoch >= params.BeaconConfig().AltairForkEpoch {
-		return altairMsgID(pmsg)
+		return postAltairMsgID(pmsg, fEpoch)
 	}
 	decodedData, err := encoder.DecodeSnappy(pmsg.Data, params.BeaconNetworkConfig().GossipMaxSize)
 	if err != nil {
@@ -69,12 +70,18 @@ func MsgID(genesisValidatorsRoot []byte, pmsg *pubsub_pb.Message) string {
 // + message.topic + snappy_decompress(message.data))[:20]. Otherwise, set message-id to the first 20 bytes of the SHA256 hash of the concatenation
 // of the following data: MESSAGE_DOMAIN_INVALID_SNAPPY, the length of the topic byte string (encoded as little-endian uint64),
 // the topic byte string, and the raw message data: i.e. SHA256(MESSAGE_DOMAIN_INVALID_SNAPPY + uint_to_bytes(uint64(len(message.topic))) + message.topic + message.data)[:20].
-func altairMsgID(pmsg *pubsub_pb.Message) string {
+func postAltairMsgID(pmsg *pubsub_pb.Message, fEpoch types.Epoch) string {
 	topic := *pmsg.Topic
 	topicLen := uint64(len(topic))
 	topicLenBytes := bytesutil.Uint64ToBytesLittleEndian(topicLen)
 
-	decodedData, err := encoder.DecodeSnappy(pmsg.Data, params.BeaconNetworkConfig().GossipMaxSize)
+	// beyond merge epoch, allow 10 Mib gossip data size
+	gossipPubSubSize := params.BeaconNetworkConfig().GossipMaxSize
+	if fEpoch >= params.BeaconConfig().BellatrixForkEpoch {
+		gossipPubSubSize = params.BeaconNetworkConfig().GossipMaxSizeBellatrix
+	}
+
+	decodedData, err := encoder.DecodeSnappy(pmsg.Data, gossipPubSubSize)
 	if err != nil {
 		totalLength := len(params.BeaconNetworkConfig().MessageDomainInvalidSnappy) + len(topicLenBytes) + int(topicLen) + len(pmsg.Data)
 		combinedData := make([]byte, 0, totalLength)
diff --git a/beacon-chain/p2p/message_id_test.go b/beacon-chain/p2p/message_id_test.go
index e3e8e1529..ab6e78395 100644
--- a/beacon-chain/p2p/message_id_test.go
+++ b/beacon-chain/p2p/message_id_test.go
@@ -64,6 +64,35 @@ func TestMessageIDFunction_HashesCorrectlyAltair(t *testing.T) {
 	assert.Equal(t, msgID, p2p.MsgID(genesisValidatorsRoot, nMsg), "Got incorrect msg id")
 }
 
+func TestMessageIDFunction_HashesCorrectlyBellatrix(t *testing.T) {
+	genesisValidatorsRoot := bytesutil.PadTo([]byte{'A'}, 32)
+	d, err := signing.ComputeForkDigest(params.BeaconConfig().BellatrixForkVersion, genesisValidatorsRoot)
+	assert.NoError(t, err)
+	tpc := fmt.Sprintf(p2p.BlockSubnetTopicFormat, d)
+	topicLen := uint64(len(tpc))
+	topicLenBytes := bytesutil.Uint64ToBytesLittleEndian(topicLen)
+	invalidSnappy := [32]byte{'J', 'U', 'N', 'K'}
+	pMsg := &pubsubpb.Message{Data: invalidSnappy[:], Topic: &tpc}
+	// Create object to hash
+	combinedObj := append(params.BeaconNetworkConfig().MessageDomainInvalidSnappy[:], topicLenBytes...)
+	combinedObj = append(combinedObj, tpc...)
+	combinedObj = append(combinedObj, pMsg.Data...)
+	hashedData := hash.Hash(combinedObj)
+	msgID := string(hashedData[:20])
+	assert.Equal(t, msgID, p2p.MsgID(genesisValidatorsRoot, pMsg), "Got incorrect msg id")
+
+	validObj := [32]byte{'v', 'a', 'l', 'i', 'd'}
+	enc := snappy.Encode(nil, validObj[:])
+	nMsg := &pubsubpb.Message{Data: enc, Topic: &tpc}
+	// Create object to hash
+	combinedObj = append(params.BeaconNetworkConfig().MessageDomainValidSnappy[:], topicLenBytes...)
+	combinedObj = append(combinedObj, tpc...)
+	combinedObj = append(combinedObj, validObj[:]...)
+	hashedData = hash.Hash(combinedObj)
+	msgID = string(hashedData[:20])
+	assert.Equal(t, msgID, p2p.MsgID(genesisValidatorsRoot, nMsg), "Got incorrect msg id")
+}
+
 func TestMsgID_WithNilTopic(t *testing.T) {
 	msg := &pubsubpb.Message{
 		Data:  make([]byte, 32),
diff --git a/beacon-chain/p2p/pubsub_filter.go b/beacon-chain/p2p/pubsub_filter.go
index d996641a0..6b848e4ec 100644
--- a/beacon-chain/p2p/pubsub_filter.go
+++ b/beacon-chain/p2p/pubsub_filter.go
@@ -37,19 +37,30 @@ func (s *Service) CanSubscribe(topic string) bool {
 	if parts[1] != "eth2" {
 		return false
 	}
-	fd, err := s.currentForkDigest()
+	phase0ForkDigest, err := s.currentForkDigest()
 	if err != nil {
 		log.WithError(err).Error("Could not determine fork digest")
 		return false
 	}
-	digest, err := forks.ForkDigestFromEpoch(params.BeaconConfig().AltairForkEpoch, s.genesisValidatorsRoot)
+	altairForkDigest, err := forks.ForkDigestFromEpoch(params.BeaconConfig().AltairForkEpoch, s.genesisValidatorsRoot)
 	if err != nil {
-		log.WithError(err).Error("Could not determine next fork digest")
+		log.WithError(err).Error("Could not determine altair fork digest")
 		return false
 	}
-	if parts[2] != fmt.Sprintf("%x", fd) && parts[2] != fmt.Sprintf("%x", digest) {
+	bellatrixForkDigest, err := forks.ForkDigestFromEpoch(params.BeaconConfig().BellatrixForkEpoch, s.genesisValidatorsRoot)
+	if err != nil {
+		log.WithError(err).Error("Could not determine merge fork digest")
 		return false
 	}
+
+	switch parts[2] {
+	case fmt.Sprintf("%x", phase0ForkDigest):
+	case fmt.Sprintf("%x", altairForkDigest):
+	case fmt.Sprintf("%x", bellatrixForkDigest):
+	default:
+		return false
+	}
+
 	if parts[4] != encoder.ProtocolSuffixSSZSnappy {
 		return false
 	}
diff --git a/beacon-chain/p2p/rpc_topic_mappings_test.go b/beacon-chain/p2p/rpc_topic_mappings_test.go
index 9af3040f5..707ddc209 100644
--- a/beacon-chain/p2p/rpc_topic_mappings_test.go
+++ b/beacon-chain/p2p/rpc_topic_mappings_test.go
@@ -102,7 +102,7 @@ func TestTopicFromMessage_CorrectType(t *testing.T) {
 		assert.Equal(t, SchemaVersionV1, version)
 	}
 
-	// After Fork
+	// Altair Fork
 	for m := range messageMapping {
 		topic, err := TopicFromMessage(m, forkEpoch)
 		assert.NoError(t, err)
diff --git a/beacon-chain/p2p/service.go b/beacon-chain/p2p/service.go
index f3c03549f..950f112e1 100644
--- a/beacon-chain/p2p/service.go
+++ b/beacon-chain/p2p/service.go
@@ -234,6 +234,10 @@ func (s *Service) Start() {
 	// current epoch.
 	s.RefreshENR()
 
+	// if the current epoch is beyond bellatrix, increase the
+	// MaxGossipSize and MaxChunkSize to 10Mb.
+	s.increaseMaxMessageSizesForBellatrix()
+
 	// Periodic functions.
 	async.RunEvery(s.ctx, params.BeaconNetworkConfig().TtfbTimeout, func() {
 		ensurePeerConnections(s.ctx, s.host, peersToWatch...)
@@ -491,3 +495,14 @@ func (s *Service) connectToBootnodes() error {
 func (s *Service) isInitialized() bool {
 	return !s.genesisTime.IsZero() && len(s.genesisValidatorsRoot) == 32
 }
+
+// increaseMaxMessageSizesForBellatrix increases the max sizes of gossip and chunk from 1 Mb to 10Mb,
+// if the current epoch is or above the configured BellatrixForkEpoch.
+func (s *Service) increaseMaxMessageSizesForBellatrix() {
+	currentSlot := slots.Since(s.genesisTime)
+	currentEpoch := slots.ToEpoch(currentSlot)
+	if currentEpoch >= params.BeaconConfig().BellatrixForkEpoch {
+		encoder.SetMaxGossipSizeForBellatrix()
+		encoder.SetMaxChunkSizeForBellatrix()
+	}
+}
diff --git a/beacon-chain/p2p/types/object_mapping.go b/beacon-chain/p2p/types/object_mapping.go
index 5d422f90b..afa626674 100644
--- a/beacon-chain/p2p/types/object_mapping.go
+++ b/beacon-chain/p2p/types/object_mapping.go
@@ -38,6 +38,9 @@ func InitializeDataMaps() {
 		bytesutil.ToBytes4(params.BeaconConfig().AltairForkVersion): func() (block.SignedBeaconBlock, error) {
 			return wrapper.WrappedAltairSignedBeaconBlock(&ethpb.SignedBeaconBlockAltair{Block: &ethpb.BeaconBlockAltair{}})
 		},
+		bytesutil.ToBytes4(params.BeaconConfig().BellatrixForkVersion): func() (block.SignedBeaconBlock, error) {
+			return wrapper.WrappedMergeSignedBeaconBlock(&ethpb.SignedBeaconBlockMerge{Block: &ethpb.BeaconBlockMerge{}})
+		},
 	}
 
 	// Reset our metadata map.
@@ -48,5 +51,8 @@ func InitializeDataMaps() {
 		bytesutil.ToBytes4(params.BeaconConfig().AltairForkVersion): func() metadata.Metadata {
 			return wrapper.WrappedMetadataV1(&ethpb.MetaDataV1{})
 		},
+		bytesutil.ToBytes4(params.BeaconConfig().BellatrixForkVersion): func() metadata.Metadata {
+			return wrapper.WrappedMetadataV1(&ethpb.MetaDataV1{})
+		},
 	}
 }
diff --git a/beacon-chain/rpc/eth/beacon/config_test.go b/beacon-chain/rpc/eth/beacon/config_test.go
index c4b953cc6..b349511f0 100644
--- a/beacon-chain/rpc/eth/beacon/config_test.go
+++ b/beacon-chain/rpc/eth/beacon/config_test.go
@@ -399,5 +399,5 @@ func TestForkSchedule_CorrectNumberOfForks(t *testing.T) {
 	resp, err := s.GetForkSchedule(context.Background(), &emptypb.Empty{})
 	require.NoError(t, err)
 	// Genesis and Altair.
-	assert.Equal(t, 2, len(resp.Data))
+	assert.Equal(t, 3, len(resp.Data))
 }
diff --git a/config/params/config.go b/config/params/config.go
index 89e517248..7d54c3270 100644
--- a/config/params/config.go
+++ b/config/params/config.go
@@ -195,4 +195,6 @@ func (b *BeaconChainConfig) InitializeForkSchedule() {
 	b.ForkVersionSchedule[bytesutil.ToBytes4(b.GenesisForkVersion)] = b.GenesisEpoch
 	// Set Altair fork data.
 	b.ForkVersionSchedule[bytesutil.ToBytes4(b.AltairForkVersion)] = b.AltairForkEpoch
+	// Set Bellatrix fork data.
+	b.ForkVersionSchedule[bytesutil.ToBytes4(b.BellatrixForkVersion)] = b.BellatrixForkEpoch
 }
diff --git a/config/params/mainnet_config.go b/config/params/mainnet_config.go
index a0f2cc56c..9776112a5 100644
--- a/config/params/mainnet_config.go
+++ b/config/params/mainnet_config.go
@@ -23,11 +23,15 @@ const (
 	genesisForkEpoch = 0
 	// Altair Fork Epoch for mainnet config.
 	mainnetAltairForkEpoch = 74240 // Oct 27, 2021, 10:56:23am UTC
+	// Placeholder for the merge epoch until it is decided
+	mainnetBellatrixForkEpoch = math.MaxUint64
 )
 
 var mainnetNetworkConfig = &NetworkConfig{
-	GossipMaxSize:                   1 << 20, // 1 MiB
-	MaxChunkSize:                    1 << 20, // 1 MiB
+	GossipMaxSize:                   1 << 20,      // 1 MiB
+	GossipMaxSizeBellatrix:          10 * 1 << 20, // 10 MiB
+	MaxChunkSize:                    1 << 20,      // 1 MiB
+	MaxChunkSizeBellatrix:           10 * 1 << 20, // 10 MiB
 	AttestationSubnetCount:          64,
 	AttestationPropagationSlotRange: 32,
 	MaxRequestBlocks:                1 << 10, // 1024
@@ -199,6 +203,7 @@ var mainnetBeaconConfig = &BeaconChainConfig{
 	ForkVersionSchedule: map[[4]byte]types.Epoch{
 		{0, 0, 0, 0}: genesisForkEpoch,
 		{1, 0, 0, 0}: mainnetAltairForkEpoch,
+		{2, 0, 0, 0}: mainnetBellatrixForkEpoch,
 		// Any further forks must be specified here by their epoch number.
 	},
 
@@ -237,6 +242,6 @@ var mainnetBeaconConfig = &BeaconChainConfig{
 	// Light client
 	MinSyncCommitteeParticipants: 1,
 
-	// Merge
+	// Bellatrix
 	TerminalBlockHashActivationEpoch: math.MaxUint64,
 }
diff --git a/config/params/minimal_config.go b/config/params/minimal_config.go
index 9bfe3816f..9e96963bb 100644
--- a/config/params/minimal_config.go
+++ b/config/params/minimal_config.go
@@ -96,6 +96,7 @@ func MinimalSpecConfig() *BeaconChainConfig {
 	minimalConfig.ForkVersionSchedule = map[[4]byte]types.Epoch{
 		{0, 0, 0, 1}: 0,
 		{1, 0, 0, 1}: math.MaxUint64,
+		{2, 0, 0, 1}: math.MaxUint64,
 	}
 	minimalConfig.SyncCommitteeSize = 32
 	minimalConfig.InactivityScoreBias = 4
diff --git a/config/params/network_config.go b/config/params/network_config.go
index 49e89adc4..7c9f046e0 100644
--- a/config/params/network_config.go
+++ b/config/params/network_config.go
@@ -10,7 +10,9 @@ import (
 // NetworkConfig defines the spec based network parameters.
 type NetworkConfig struct {
 	GossipMaxSize                   uint64        `yaml:"GOSSIP_MAX_SIZE"`                    // GossipMaxSize is the maximum allowed size of uncompressed gossip messages.
-	MaxChunkSize                    uint64        `yaml:"MAX_CHUNK_SIZE"`                     // MaxChunkSize is the the maximum allowed size of uncompressed req/resp chunked responses.
+	GossipMaxSizeBellatrix          uint64        `yaml:"GOSSIP_MAX_SIZE_BELLATRIX"`          // GossipMaxSizeBellatrix is the maximum allowed size of uncompressed gossip messages after the bellatrix epoch.
+	MaxChunkSize                    uint64        `yaml:"MAX_CHUNK_SIZE"`                     // MaxChunkSize is the maximum allowed size of uncompressed req/resp chunked responses.
+	MaxChunkSizeBellatrix           uint64        `yaml:"MAX_CHUNK_SIZE_BELLATRIX"`           // MaxChunkSizeBellatrix is the maximum allowed size of uncompressed req/resp chunked responses after the bellatrix epoch.
 	AttestationSubnetCount          uint64        `yaml:"ATTESTATION_SUBNET_COUNT"`           // AttestationSubnetCount is the number of attestation subnets used in the gossipsub protocol.
 	AttestationPropagationSlotRange types.Slot    `yaml:"ATTESTATION_PROPAGATION_SLOT_RANGE"` // AttestationPropagationSlotRange is the maximum number of slots during which an attestation can be propagated.
 	MaxRequestBlocks                uint64        `yaml:"MAX_REQUEST_BLOCKS"`                 // MaxRequestBlocks is the maximum number of blocks in a single request.