diff --git a/internal/common/omci/onu_mib_db.go b/internal/common/omci/onu_mib_db.go
index e9fabed..2902fd2 100644
--- a/internal/common/omci/onu_mib_db.go
+++ b/internal/common/omci/onu_mib_db.go
@@ -21,6 +21,7 @@
 	"encoding/binary"
 	"encoding/hex"
 
+	"github.com/opencord/bbsim/internal/common"
 	me "github.com/opencord/omci-lib-go/v2/generated"
 )
 
@@ -70,6 +71,7 @@
 	cardHolderOnuType byte = 0x01 // ONU is a single piece of integrated equipment
 	ethernetUnitType  byte = 0x2f // Ethernet BASE-T
 	xgsPonUnitType    byte = 0xee // XG-PON10G10
+	gPonUnitType      byte = 0xf5 // GPON12441244
 	potsUnitType      byte = 0x20 // POTS
 	cardHolderSlotID  byte = 0x01
 	tcontSlotId       byte = 0x80 // why is this not the same as the cardHolderSlotID, it does not point to anything
@@ -92,7 +94,7 @@
 
 // creates a MIB database for a ONU
 // CircuitPack and CardHolder are static, everything else can be configured
-func GenerateMibDatabase(ethUniPortCount int, potsUniPortCount int) (*MibDb, error) {
+func GenerateMibDatabase(ethUniPortCount int, potsUniPortCount int, technology common.PonTechnology) (*MibDb, error) {
 
 	mibDb := MibDb{
 		items: []MibDbEntry{},
@@ -116,12 +118,21 @@
 	//	},
 	//})
 
-	// circuitPack XG-PON10G10
+	// ANI circuitPack
+	var aniCPType byte
+
+	switch technology {
+	case common.XGSPON:
+		aniCPType = xgsPonUnitType
+	case common.GPON:
+		aniCPType = gPonUnitType
+	}
+
 	mibDb.items = append(mibDb.items, MibDbEntry{
 		me.CircuitPackClassID,
 		circuitPackEntityID,
 		me.AttributeValueMap{
-			me.CircuitPack_Type:          xgsPonUnitType,
+			me.CircuitPack_Type:          aniCPType,
 			me.CircuitPack_NumberOfPorts: 1, // NOTE is this the ANI port? must be
 			me.CircuitPack_SerialNumber:  ToOctets("BBSM-Circuit-Pack-ani", 20),
 			me.CircuitPack_Version:       ToOctets("v0.0.1", 20),
diff --git a/internal/common/omci/onu_mib_db_test.go b/internal/common/omci/onu_mib_db_test.go
index 378ac6e..2794aa4 100644
--- a/internal/common/omci/onu_mib_db_test.go
+++ b/internal/common/omci/onu_mib_db_test.go
@@ -19,6 +19,7 @@
 import (
 	"testing"
 
+	"github.com/opencord/bbsim/internal/common"
 	"github.com/opencord/omci-lib-go/v2"
 	me "github.com/opencord/omci-lib-go/v2/generated"
 	"github.com/stretchr/testify/assert"
@@ -56,7 +57,7 @@
 
 func Test_GenerateMibDatabase(t *testing.T) {
 	const uniPortCount = 4
-	mibDb, err := GenerateMibDatabase(uniPortCount, 0)
+	mibDb, err := GenerateMibDatabase(uniPortCount, 0, common.XGSPON)
 
 	expectedItems := 9                     //ONU-G + 2 Circuit Packs (4 messages each)
 	expectedItems += 2 * uniPortCount      // 1 PPTP and 1 UniG per UNI
@@ -94,7 +95,7 @@
 func Test_GenerateMibDatabase_withPots(t *testing.T) {
 	const uniPortCount = 4
 	const potsPortCount = 1
-	mibDb, err := GenerateMibDatabase(uniPortCount, potsPortCount)
+	mibDb, err := GenerateMibDatabase(uniPortCount, potsPortCount, common.XGSPON)
 
 	expectedItems := 13                                      //ONU-G + 3 Circuit Packs (4 messages each)
 	expectedItems += 2 * (uniPortCount + potsPortCount)      // 1 PPTP and 1 UniG per UNI
diff --git a/internal/common/option_test.go b/internal/common/option_test.go
index 2a57624..bf8d139 100644
--- a/internal/common/option_test.go
+++ b/internal/common/option_test.go
@@ -17,8 +17,11 @@
 package common
 
 import (
-	"gotest.tools/assert"
+	"fmt"
 	"testing"
+
+	"github.com/imdario/mergo"
+	"gotest.tools/assert"
 )
 
 func TestLoadBBSimServices(t *testing.T) {
@@ -36,3 +39,186 @@
 	assert.Equal(t, services[0].NeedsIgmp, false)
 	assert.Equal(t, services[0].TechnologyProfileID, 64)
 }
+
+func TestLoadPonsConfigDefaults(t *testing.T) {
+	Config = getDefaultOps()
+	// The default options define 1 PON per OLT
+	// and 1 ONU per PON
+
+	Services = []ServiceYaml{
+		{
+			Name: "test",
+		},
+	}
+
+	ponsConf, err := getDefaultPonsConfig()
+
+	assert.NilError(t, err, "Can't get defaults")
+
+	assert.Equal(t, ponsConf.Number, uint32(1))
+	assert.Equal(t, len(ponsConf.Ranges), 1)
+
+	ranges := ponsConf.Ranges
+
+	//The default should replicate the old way bbsim used to compute ranges
+	assert.Equal(t, ranges[0].PonRange, IdRange{0, 0})
+	assert.Equal(t, ranges[0].Technology, XGSPON.String())
+	assert.Equal(t, ranges[0].OnuRange, IdRange{defaultOnuIdStart, defaultOnuIdStart})
+	assert.Equal(t, ranges[0].AllocIdRange, IdRange{defaultAllocIdStart, defaultAllocIdStart + 4})
+	assert.Equal(t, ranges[0].GemportRange, IdRange{defaultGemportIdStart, defaultGemportIdStart + 32})
+
+	assert.NilError(t, validatePonsConfig(ponsConf), "Configuration is not valid")
+}
+
+func TestLoadPonsConfigFile(t *testing.T) {
+
+	Config = getDefaultOps()
+
+	Services = []ServiceYaml{
+		{
+			Name: "test",
+		},
+	}
+
+	ponsConf, err := getDefaultPonsConfig()
+
+	assert.NilError(t, err, "Can't get defaults")
+
+	yamlConf, err := loadBBSimPons("../../configs/pon-interfaces.yaml")
+
+	assert.NilError(t, err, "Can't read config file")
+
+	// merging Yaml and Default Values
+	err = mergo.Merge(ponsConf, yamlConf, mergo.WithOverride)
+	assert.NilError(t, err, "Can't merge YAML and Config")
+
+	assert.Equal(t, ponsConf.Number, uint32(16))
+	assert.Equal(t, len(ponsConf.Ranges), 1)
+
+	ranges := ponsConf.Ranges
+
+	assert.Equal(t, ranges[0].PonRange, IdRange{0, 15})
+	assert.Equal(t, ranges[0].Technology, XGSPON.String())
+	assert.Equal(t, ranges[0].OnuRange, IdRange{1, 255})
+	assert.Equal(t, ranges[0].AllocIdRange, IdRange{256, 1024})
+	assert.Equal(t, ranges[0].GemportRange, IdRange{256, 1024})
+
+	assert.NilError(t, validatePonsConfig(ponsConf), "Configuration is not valid")
+}
+
+func getTestPonsConfiguration() *PonPortsConfig {
+	return &PonPortsConfig{
+		Number: 16,
+		Ranges: []PonRangeConfig{
+			{
+				PonRange:     IdRange{0, 7},
+				Technology:   GPON.String(),
+				OnuRange:     IdRange{defaultOnuIdStart, defaultOnuIdStart},
+				AllocIdRange: IdRange{defaultAllocIdStart, defaultAllocIdStart + 4},
+				GemportRange: IdRange{defaultGemportIdStart, defaultGemportIdStart + 32},
+			},
+			{
+				PonRange:     IdRange{8, 15},
+				Technology:   XGSPON.String(),
+				OnuRange:     IdRange{defaultOnuIdStart, defaultOnuIdStart},
+				AllocIdRange: IdRange{defaultAllocIdStart, defaultAllocIdStart + 4},
+				GemportRange: IdRange{defaultGemportIdStart, defaultGemportIdStart + 32},
+			},
+		},
+	}
+}
+
+func TestPonsValidationTechnology(t *testing.T) {
+	ponsConf := getTestPonsConfiguration()
+	assert.NilError(t, validatePonsConfig(ponsConf), "Test configuration is not valid")
+
+	ponsConf.Ranges[0].Technology = XGSPON.String()
+	assert.NilError(t, validatePonsConfig(ponsConf), "Correct technology considered invalid")
+
+	ponsConf.Ranges[0].Technology = GPON.String()
+	assert.NilError(t, validatePonsConfig(ponsConf), "Correct technology considered invalid")
+
+	ponsConf.Ranges[0].Technology = "TEST"
+	assert.ErrorContains(t, validatePonsConfig(ponsConf), "technology", "Incorrect technology considered valid")
+}
+
+func TestPonsValidationPortsInRanges(t *testing.T) {
+	ponsConf := getTestPonsConfiguration()
+	assert.NilError(t, validatePonsConfig(ponsConf), "Test configuration is not valid")
+
+	//The second range now misses pon 8
+	ponsConf.Ranges[1].PonRange.StartId = 9
+
+	assert.ErrorContains(t, validatePonsConfig(ponsConf), "not-defined", "Missing pon definition considered valid")
+
+	//The second range defines pon 7 a second time
+	ponsConf.Ranges[1].PonRange.StartId = 7
+
+	assert.ErrorContains(t, validatePonsConfig(ponsConf), "duplicate", "Duplicate pon definition considered valid")
+
+	//Get back to a known good configuration
+	ponsConf = getTestPonsConfiguration()
+	//The second range uses an Id that is out of range
+	ponsConf.Ranges[1].PonRange.EndId = 16
+
+	assert.ErrorContains(t, validatePonsConfig(ponsConf), "max", "Out of range pon definition considered valid")
+
+	//Fix the start of the second range
+	ponsConf.Ranges[1].PonRange.EndId = 15
+
+	ponsConf.Number = 0
+
+	assert.ErrorContains(t, validatePonsConfig(ponsConf), "no-pon-ports", "Zero pons considered valid")
+}
+
+func TestPonsValidationRangeLimits(t *testing.T) {
+	ponsConf := getTestPonsConfiguration()
+	assert.NilError(t, validatePonsConfig(ponsConf), "Test configuration is not valid")
+
+	ponsConf.Ranges[0].PonRange = IdRange{0, 0}
+	ponsConf.Ranges[1].PonRange = IdRange{1, 15}
+
+	assert.NilError(t, validatePonsConfig(ponsConf), "Single pon range considered invalid")
+
+	//Get back to a known good configuration
+	ponsConf = getTestPonsConfiguration()
+	ponsConf.Ranges[0].PonRange = IdRange{5, 4}
+
+	assert.ErrorContains(t, validatePonsConfig(ponsConf), "limits", "Invalid pons range limits considered valid")
+
+	ponsConf = getTestPonsConfiguration()
+	ponsConf.Ranges[0].OnuRange = IdRange{5, 4}
+
+	assert.ErrorContains(t, validatePonsConfig(ponsConf), "limits", "Invalid onus range limits considered valid")
+
+	ponsConf = getTestPonsConfiguration()
+	ponsConf.Ranges[0].AllocIdRange = IdRange{5, 4}
+
+	assert.ErrorContains(t, validatePonsConfig(ponsConf), "limits", "Invalid alloc-ids range limits considered valid")
+
+	ponsConf = getTestPonsConfiguration()
+	ponsConf.Ranges[0].GemportRange = IdRange{5, 4}
+
+	assert.ErrorContains(t, validatePonsConfig(ponsConf), "limits", "Invalid gemports range limits considered valid")
+}
+
+func TestGetPonConfigById(t *testing.T) {
+	PonsConfig = getTestPonsConfiguration()
+
+	for id := uint32(0); id < PonsConfig.Number-1; id++ {
+		conf, err := GetPonConfigById(id)
+		assert.NilError(t, err, fmt.Sprintf("Cannot get configuration for pon %d", id))
+
+		if id > conf.PonRange.EndId || id < conf.PonRange.StartId {
+			assert.NilError(t, err, fmt.Sprintf("Got wrong configuration for pon %d", id))
+		}
+	}
+
+	_, err := GetPonConfigById(16)
+
+	assert.Assert(t, err != nil, "Invalid pon id returned configuration")
+
+	_, err = GetPonConfigById(100)
+
+	assert.Assert(t, err != nil, "Invalid pon id returned configuration")
+}
diff --git a/internal/common/options.go b/internal/common/options.go
index 000a8dc..58cec20 100644
--- a/internal/common/options.go
+++ b/internal/common/options.go
@@ -88,7 +88,6 @@
 	NniPorts           uint32 `yaml:"nni_ports"`
 	NniSpeed           uint32 `yaml:"nni_speed"`
 	OnusPonPort        uint32 `yaml:"onus_per_port"`
-	Technology         string `yaml:"technology"`
 	ID                 int    `yaml:"id"`
 	OltRebootDelay     int    `yaml:"reboot_delay"`
 	PortStatsInterval  int    `yaml:"port_stats_interval"`
@@ -97,9 +96,77 @@
 	PotsPorts          uint32 `yaml:"pots_ports"`
 }
 
+type PonPortsConfig struct {
+	Number uint32           `yaml:"num_pon_ports"`
+	Ranges []PonRangeConfig `yaml:"ranges"`
+}
+
+type IdRange struct {
+	StartId uint32 `yaml:"start"`
+	EndId   uint32 `yaml:"end"`
+}
+
+type PonTechnology int
+
+var ponTechnologyValues = []string{
+	"GPON", "XGS-PON",
+}
+
+func (t PonTechnology) String() string {
+	return ponTechnologyValues[t]
+}
+
+const (
+	GPON PonTechnology = iota
+	XGSPON
+)
+
+func PonTechnologyFromString(s string) (PonTechnology, error) {
+	for i, val := range ponTechnologyValues {
+		if val == s {
+			return PonTechnology(i), nil
+		}
+	}
+	log.WithFields(log.Fields{
+		"ValidValues": strings.Join(ponTechnologyValues[:], ", "),
+	}).Errorf("%s-is-not-a-valid-pon-technology", s)
+	return -1, fmt.Errorf("%s-is-not-a-valid-pon-technology", s)
+}
+
+//Constants for default allocation ranges
+const (
+	defaultOnuIdStart          = 1
+	defaultAllocIdStart        = 1024
+	defaultGemPortIdPerAllocId = 8
+	defaultGemportIdStart      = 1024
+)
+
+type PonRangeConfig struct {
+	PonRange     IdRange `yaml:"pon_id_range"`
+	Technology   string  `yaml:"tech"`
+	OnuRange     IdRange `yaml:"onu_id_range"`
+	AllocIdRange IdRange `yaml:"alloc_id_range"`
+	GemportRange IdRange `yaml:"gemport_id_range"`
+}
+
+func GetPonConfigById(id uint32) (*PonRangeConfig, error) {
+	if PonsConfig == nil {
+		return nil, fmt.Errorf("pons-config-nil")
+	}
+
+	for _, r := range PonsConfig.Ranges {
+		if id >= r.PonRange.StartId && id <= r.PonRange.EndId {
+			return &r, nil
+		}
+	}
+
+	return nil, fmt.Errorf("pon-config-for-id-%d-not-found", id)
+}
+
 type BBSimConfig struct {
 	ConfigFile             string
 	ServiceConfigFile      string
+	PonsConfigFile         string
 	DhcpRetry              bool    `yaml:"dhcp_retry"`
 	AuthRetry              bool    `yaml:"auth_retry"`
 	LogLevel               string  `yaml:"log_level"`
@@ -172,8 +239,9 @@
 }
 
 var (
-	Config   *GlobalConfig
-	Services []ServiceYaml
+	Config     *GlobalConfig
+	Services   []ServiceYaml
+	PonsConfig *PonPortsConfig
 )
 
 // Load the BBSim configuration. This is a combination of CLI parameters and YAML files
@@ -221,6 +289,31 @@
 
 	Services = services
 
+	//A blank filename means we should fall back to bbsim defaults
+	if Config.BBSim.PonsConfigFile == "" {
+		PonsConfig, err = getDefaultPonsConfig()
+		if err != nil {
+			log.WithFields(log.Fields{
+				"err": err,
+			}).Fatal("Can't load Pon interfaces defaults.")
+		}
+	} else {
+		PonsConfig, err = loadBBSimPons(Config.BBSim.PonsConfigFile)
+
+		if err != nil {
+			log.WithFields(log.Fields{
+				"file": Config.BBSim.PonsConfigFile,
+				"err":  err,
+			}).Fatal("Can't read services file")
+		}
+	}
+
+	if err := validatePonsConfig(PonsConfig); err != nil {
+		log.WithFields(log.Fields{
+			"file": Config.BBSim.PonsConfigFile,
+			"err":  err,
+		}).Fatal("Invalid Pon interfaces configuration")
+	}
 }
 
 func readCliParams() *GlobalConfig {
@@ -229,6 +322,7 @@
 
 	configFile := flag.String("config", conf.BBSim.ConfigFile, "Configuration file path")
 	servicesFile := flag.String("services", conf.BBSim.ServiceConfigFile, "Service Configuration file path")
+	ponsFile := flag.String("pon_port_config_file", conf.BBSim.PonsConfigFile, "Pon Interfaces Configuration file path")
 	sadisBpFormat := flag.String("bp_format", conf.BBSim.BandwidthProfileFormat, "Bandwidth profile format, 'mef' or 'ietf'")
 
 	olt_id := flag.Int("olt_id", conf.Olt.ID, "OLT device ID")
@@ -275,6 +369,7 @@
 	conf.Olt.OmciResponseRate = uint8(*omci_response_rate)
 	conf.BBSim.ConfigFile = *configFile
 	conf.BBSim.ServiceConfigFile = *servicesFile
+	conf.BBSim.PonsConfigFile = *ponsFile
 	conf.BBSim.CpuProfile = profileCpu
 	conf.BBSim.LogLevel = *logLevel
 	conf.BBSim.LogCaller = *logCaller
@@ -309,8 +404,12 @@
 
 	c := &GlobalConfig{
 		BBSimConfig{
-			ConfigFile:             "configs/bbsim.yaml",
-			ServiceConfigFile:      "configs/att-services.yaml",
+			ConfigFile:        "configs/bbsim.yaml",
+			ServiceConfigFile: "configs/att-services.yaml",
+			// PonsConfigFile is left intentionally blank here
+			// to use the default values computed at runtime depending
+			// on the loaded Services
+			PonsConfigFile:         "",
 			LogLevel:               "debug",
 			LogCaller:              false,
 			Delay:                  200,
@@ -341,7 +440,6 @@
 			NniPorts:           1,
 			NniSpeed:           10000, //Mbps
 			OnusPonPort:        1,
-			Technology:         "XGS-PON",
 			ID:                 0,
 			OltRebootDelay:     60,
 			PortStatsInterval:  20,
@@ -357,6 +455,35 @@
 	return c
 }
 
+func getDefaultPonsConfig() (*PonPortsConfig, error) {
+
+	if Config == nil {
+		return nil, fmt.Errorf("Config is nil")
+	}
+	if Services == nil {
+		return nil, fmt.Errorf("Services is nil")
+	}
+
+	//The default should replicate the old way bbsim used to compute resource ranges based on the configuration
+	// 1 allocId per Service * UNI
+	allocIdPerOnu := uint32(Config.Olt.UniPorts * uint32(len(Services)))
+	return &PonPortsConfig{
+		Number: Config.Olt.PonPorts,
+		Ranges: []PonRangeConfig{
+			{
+				PonRange:   IdRange{0, Config.Olt.PonPorts - 1},
+				Technology: XGSPON.String(),
+				// we need one ONU ID available per ONU, but the smaller the range the smaller the pool created in the openolt adapter
+				OnuRange: IdRange{defaultOnuIdStart, defaultOnuIdStart + (Config.Olt.OnusPonPort - 1)},
+				// 1 allocId per Service * UNI * ONU
+				AllocIdRange: IdRange{defaultAllocIdStart, defaultAllocIdStart + (Config.Olt.OnusPonPort * allocIdPerOnu)},
+				// up to 8 gemport-id per tcont/alloc-id
+				GemportRange: IdRange{defaultGemportIdStart, defaultGemportIdStart + Config.Olt.OnusPonPort*allocIdPerOnu*defaultGemPortIdPerAllocId},
+			},
+		},
+	}, nil
+}
+
 // LoadBBSimConf loads the BBSim configuration from a YAML file
 func loadBBSimConf(filename string) (*GlobalConfig, error) {
 	yamlConfig := getDefaultOps()
@@ -378,6 +505,84 @@
 	return yamlConfig, nil
 }
 
+// loadBBSimPons loads the configuration of PON interfaces from a YAML file
+func loadBBSimPons(filename string) (*PonPortsConfig, error) {
+	yamlPonsConfig, err := getDefaultPonsConfig()
+	if err != nil {
+		log.WithFields(log.Fields{
+			"err": err,
+		}).Error("Can't load Pon interfaces defaults.")
+		return nil, err
+	}
+
+	yamlFile, err := ioutil.ReadFile(filename)
+	if err != nil {
+		log.WithFields(log.Fields{
+			"err":      err,
+			"filename": filename,
+		}).Error("Cannot load Pon interfaces configuration file. Using defaults.")
+		return yamlPonsConfig, nil
+	}
+
+	err = yaml.Unmarshal(yamlFile, yamlPonsConfig)
+	if err != nil {
+		return nil, err
+	}
+
+	return yamlPonsConfig, nil
+}
+
+// validatePonsConfig checks if the configuration to use for the definition of Pon interfaces is valid
+func validatePonsConfig(pons *PonPortsConfig) error {
+
+	if pons.Number == 0 {
+		return fmt.Errorf("no-pon-ports")
+	}
+
+	definedPorts := make([]int, pons.Number)
+
+	for rIndex, resRange := range pons.Ranges {
+		if _, err := PonTechnologyFromString(resRange.Technology); err != nil {
+			return err
+		}
+
+		if resRange.PonRange.EndId < resRange.PonRange.StartId {
+			return fmt.Errorf("invalid-pon-ports-limits-in-range-%d", rIndex)
+		}
+
+		//Keep track of the defined pons
+		for p := resRange.PonRange.StartId; p <= resRange.PonRange.EndId; p++ {
+			if p > uint32(len(definedPorts)-1) {
+				return fmt.Errorf("pon-port-%d-in-range-%d-but-max-is-%d", p, rIndex, pons.Number-1)
+			}
+			definedPorts[p]++
+
+			if definedPorts[p] > 1 {
+				return fmt.Errorf("pon-port-%d-has-duplicate-definition-in-range-%d", p, rIndex)
+			}
+		}
+
+		if resRange.OnuRange.EndId < resRange.OnuRange.StartId {
+			return fmt.Errorf("invalid-onus-limits-in-range-%d", rIndex)
+		}
+		if resRange.AllocIdRange.EndId < resRange.AllocIdRange.StartId {
+			return fmt.Errorf("invalid-allocid-limits-in-range-%d", rIndex)
+		}
+		if resRange.GemportRange.EndId < resRange.GemportRange.StartId {
+			return fmt.Errorf("invalid-gemport-limits-in-range-%d", rIndex)
+		}
+	}
+
+	//Check if the ranges define all the pons
+	for i, num := range definedPorts {
+		if num < 1 {
+			return fmt.Errorf("pon-port-%d-is-not-defined-in-ranges", i)
+		}
+	}
+
+	return nil
+}
+
 // LoadBBSimServices parses a file describing the services that need to be created for each UNI
 func loadBBSimServices(filename string) ([]ServiceYaml, error) {