Diameter Gx Interface Documentation

Policy and Charging Rules Function (PCRF) Interface

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Table of Contents

1. Overview
2. Gx Interface Basics
3. Diameter Protocol
4. Credit Control Messages
5. Policy and Charging Rules
6. Configuration
7. Message Flows
8. Error Handling
9. Troubleshooting

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Overview

The Gx interface connects PGW-C to the PCRF (Policy and Charging Rules Function) or PCF (Policy Control Function) in 5G networks. This interface enables:

• Dynamic Policy Control - Real-time QoS and policy enforcement
• Charging Control - Credit authorization and usage tracking
• Service Awareness - Application-level traffic differentiation
• Subscriber Profile Management - Per-user policy application

Gx in the Network Architecture

Key Functions

Function	Description
Policy Provisioning	PCRF provides PCC rules defining how to handle traffic
QoS Control	Dynamic adjustment of bitrates and QoS parameters
Charging Control	Credit authorization for prepaid/postpaid scenarios
Gating Control	Enable/disable traffic flows based on policy
Usage Monitoring	Track data consumption per service

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Gx Interface Basics

3GPP Reference

• Specification: 3GPP TS 29.212
• Diameter Application ID: 16777238 (Gx)
• Protocol: Diameter Base Protocol (RFC 6733)

Session Concept

Each UE PDN connection has a corresponding Gx session identified by a Session-ID. This session:

• Created when UE attaches (CCR-Initial)
• Updated during the connection lifetime (CCR-Update) - optional
• Terminated when UE detaches (CCR-Termination)

Session ID Format

Session-ID: <Origin-Host>;<high32>;<low32>[;<optional>]
Example: omni-pgw_c.epc.mnc999.mcc999.3gppnetwork.org;1234567890;98765

Components:

• Origin-Host: PGW-C's Diameter identity
• high32: High 32 bits of unique identifier
• low32: Low 32 bits of unique identifier

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Diameter Protocol

Message Structure

Diameter messages are binary-encoded with the following structure:

Diameter Header (20 bytes)
├── Version (1 byte) = 1
├── Message Length (3 bytes)
├── Flags (1 byte)
│   ├── R: Request (1) / Answer (0)
│   ├── P: Proxiable
│   ├── E: Error
│   └── T: Potentially retransmitted
├── Command Code (3 bytes)
├── Application ID (4 bytes) = 16777238 (Gx)
├── Hop-by-Hop ID (4 bytes)
└── End-to-End ID (4 bytes)

AVPs (Attribute-Value Pairs)
├── AVP Header
│   ├── AVP Code
│   ├── Flags (V, M, P)
│   ├── AVP Length
│   └── Vendor ID (optional)
└── AVP Data

Key Diameter Concepts

AVP (Attribute-Value Pair):

• Basic data unit in Diameter
• Contains a code, flags, and value
• Can be nested (Grouped AVP)

Command:

• Request/Answer pair
• CCR (Credit-Control-Request) / CCA (Credit-Control-Answer)

Result Codes:

• 2001 - DIAMETER_SUCCESS
• 3xxx - Protocol errors
• 4xxx - Transient failures
• 5xxx - Permanent failures

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Credit Control Messages

PGW-C uses the Diameter Credit Control Application (RFC 4006) for Gx.

Message Types

CCR-Initial (Credit Control Request - Initial)

When: UE creates a new PDN connection

Purpose:

• Request initial policy and charging rules
• Provide UE and network context to PCRF
• Obtain QoS parameters and charging authorization

Key AVPs Sent by PGW-C:

AVP Name	AVP Code	Type	Description
Session-Id	263	UTF8String	Unique Gx session identifier
Auth-Application-Id	258	Unsigned32	16777238 (Gx)
Origin-Host	264	DiamIdent	PGW-C's Diameter identity
Origin-Realm	296	DiamIdent	PGW-C's Diameter realm
Destination-Realm	283	DiamIdent	PCRF's realm
CC-Request-Type	416	Enumerated	1 = INITIAL_REQUEST
CC-Request-Number	415	Unsigned32	Sequence number (starts at 0)
Subscription-Id	443	Grouped	UE identifier (IMSI/MSISDN)
Called-Station-Id	30	UTF8String	APN name
Framed-IP-Address	8	OctetString	Allocated UE IPv4 address
IP-CAN-Type	1027	Enumerated	5 = 3GPP-EPS
RAT-Type	1032	Enumerated	1004 = EUTRAN
QoS-Information	1016	Grouped	Current QoS (AMBR)
Network-Request-Support	1024	Enumerated	Network-initiated procedures
Supported-Features	628	Grouped	Gx feature list

Example CCR-I Structure:

CCR (Command Code: 272, Request)
├── Session-Id: "pgw_c.example.com;123;456"
├── Auth-Application-Id: 16777238
├── Origin-Host: "omni-pgw_c.epc.mnc999.mcc999.3gppnetwork.org"
├── Origin-Realm: "epc.mnc999.mcc999.3gppnetwork.org"
├── Destination-Realm: "epc.mnc999.mcc999.3gppnetwork.org"
├── CC-Request-Type: INITIAL_REQUEST (1)
├── CC-Request-Number: 0
├── Subscription-Id (Grouped)
│   ├── Subscription-Id-Type: END_USER_IMSI (1)
│   └── Subscription-Id-Data: "310260123456789"
├── Called-Station-Id: "internet"
├── Framed-IP-Address: 100.64.1.42
├── IP-CAN-Type: 3GPP-EPS (5)
├── RAT-Type: EUTRAN (1004)
├── QoS-Information (Grouped)
│   ├── APN-Aggregate-Max-Bitrate-UL: 100000000 (100 Mbps)
│   └── APN-Aggregate-Max-Bitrate-DL: 50000000 (50 Mbps)
├── Network-Request-Support: 1
└── Supported-Features: [...]

CCA-Initial (Credit Control Answer - Initial)

Sent by: PCRF in response to CCR-I

Purpose:

• Authorize or reject the session
• Provide PCC rules for traffic handling
• Specify QoS parameters

Key AVPs Received by PGW-C:

AVP Name	AVP Code	Description
Result-Code	268	Success (2001) or error code
Experimental-Result	297	Vendor-specific result codes
QoS-Information	1016	Authorized QoS (may differ from request)
Charging-Rule-Install	1001	PCC rules to activate
Charging-Rule-Definition	1003	Inline rule definitions
Default-EPS-Bearer-QoS	1049	QoS for default bearer

Success Response Example:

CCA (Command Code: 272, Answer)
├── Session-Id: "pgw_c.example.com;123;456"
├── Result-Code: DIAMETER_SUCCESS (2001)
├── Origin-Host: "pcrf.example.com"
├── Origin-Realm: "example.com"
├── Auth-Application-Id: 16777238
├── CC-Request-Type: INITIAL_REQUEST (1)
├── CC-Request-Number: 0
├── QoS-Information (Grouped)
│   ├── APN-Aggregate-Max-Bitrate-UL: 50000000 (50 Mbps - reduced)
│   └── APN-Aggregate-Max-Bitrate-DL: 100000000 (100 Mbps - increased)
├── Charging-Rule-Install (Grouped)
│   ├── Charging-Rule-Name: "default_internet_rule"
│   └── Charging-Rule-Name: "video_streaming_rule"
└── Charging-Rule-Definition (Grouped)
    ├── Charging-Rule-Name: "default_internet_rule"
    ├── QoS-Information: {...}
    └── Precedence: 1000

CCR-Termination (Credit Control Request - Termination)

When: UE detaches or PDN connection is deleted

Purpose:

• Notify PCRF of session termination
• Final accounting/charging record

Key Differences from CCR-I:

• CC-Request-Type: TERMINATION_REQUEST (3)
• May include usage statistics
• Simplified AVP set

Example CCR-T:

CCR (Command Code: 272, Request)
├── Session-Id: "pgw_c.example.com;123;456"
├── Auth-Application-Id: 16777238
├── Origin-Host: "omni-pgw_c.epc.mnc999.mcc999.3gppnetwork.org"
├── Origin-Realm: "epc.mnc999.mcc999.3gppnetwork.org"
├── Destination-Realm: "epc.mnc999.mcc999.3gppnetwork.org"
├── CC-Request-Type: TERMINATION_REQUEST (3)
├── CC-Request-Number: 1
└── Termination-Cause: DIAMETER_LOGOUT (1)

CCA-Termination

Sent by: PCRF in response to CCR-T

Purpose:

• Acknowledge session termination
• No policy rules returned

Example CCA-T:

CCA (Command Code: 272, Answer)
├── Session-Id: "pgw_c.example.com;123;456"
├── Result-Code: DIAMETER_SUCCESS (2001)
├── Origin-Host: "pcrf.example.com"
├── Origin-Realm: "example.com"
├── Auth-Application-Id: 16777238
├── CC-Request-Type: TERMINATION_REQUEST (3)
└── CC-Request-Number: 1

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Policy and Charging Rules

PCC Rule Structure

A PCC (Policy and Charging Control) Rule defines how to handle specific traffic flows:

Rule Components

1. Rule Name:

• Unique identifier for the rule
• Example: "video_streaming_rule"

2. Precedence:

• Lower number = higher priority
• Range: 0-65535
• Used when multiple rules match

3. Flow Filters (TFT - Traffic Flow Template):

• Defines which packets match this rule
• Examples:
  • IP 5-tuple: Protocol, Src/Dst IP, Src/Dst Port
  • "permit out ip from any to 8.8.8.8 80"

4. QoS Information:

• QCI (QoS Class Identifier): 1-9 (standardized), 128-254 (operator-specific)
  • QCI 1: Conversational Voice
  • QCI 5: IMS Signaling
  • QCI 9: Default Internet
• ARP (Allocation and Retention Priority): Pre-emption capability
• MBR/GBR: Maximum/Guaranteed Bit Rates

5. Charging Information:

• Rating Group: Identifies charging category (used by OCS - see Diameter Gy Interface)
• Metering Method: Volume, time, or event-based
• Online/Offline Charging: OCS (prepaid via Diameter Gy) vs. offline CDRs (postpaid - see Data CDR Format)

6. Gating Status:

• OPEN: Allow traffic
• CLOSED: Block traffic

Dynamic Rule Provisioning

PCRF can provide rules in two ways:

1. Predefined Rules (by name):

Charging-Rule-Install (Grouped)
├── Charging-Rule-Name: "gold_subscriber_internet"
└── Charging-Rule-Name: "video_qos_boost"

2. Dynamic Rules (inline definition):

Charging-Rule-Definition (Grouped)
├── Charging-Rule-Name: "dynamic_rule_123"
├── Precedence: 100
├── Flow-Information (Grouped)
│   ├── Flow-Description: "permit out ip from any to 192.0.2.0/24"
│   └── Flow-Direction: DOWNLINK
├── QoS-Information (Grouped)
│   ├── QoS-Class-Identifier: 5
│   ├── Max-Requested-Bandwidth-UL: 10000000
│   └── Max-Requested-Bandwidth-DL: 50000000
└── Rating-Group: 1000

QoS Information AVP

APN-AMBR (Aggregate Maximum Bit Rate):

Applies to all non-GBR bearers for this APN:

QoS-Information (Grouped)
├── APN-Aggregate-Max-Bitrate-UL: 100000000  # 100 Mbps
└── APN-Aggregate-Max-Bitrate-DL: 200000000  # 200 Mbps

PGW-C Response:

• Updates internal AMBR state
• Sends Session Modification Request to PGW-U with updated QER

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Configuration

Basic Gx Configuration

Edit config/runtime.exs:

config :pgw_c,
  diameter: %{
    # IP address to listen for Diameter connections
    listen_ip: "0.0.0.0",

    # PGW-C's Diameter identity (Origin-Host)
    host: "omni-pgw_c.epc.mnc999.mcc999.3gppnetwork.org",

    # PGW-C's Diameter realm (Origin-Realm)
    realm: "epc.mnc999.mcc999.3gppnetwork.org",

    # List of PCRF peers
    peer_list: [
      %{
        # PCRF Diameter identity
        host: "pcrf.epc.mnc999.mcc999.3gppnetwork.org",

        # PCRF realm (usually same as PGW-C realm)
        realm: "epc.mnc999.mcc999.3gppnetwork.org",

        # PCRF IP address
        ip: "10.0.0.30",

        # Whether PGW-C initiates connection to PCRF
        # true = PGW-C connects to PCRF
        # false = Wait for PCRF to connect
        initiate_connection: true
      }
    ]
  }

Multiple PCRF Peers

For redundancy or geographic distribution:

config :pgw_c,
  diameter: %{
    listen_ip: "0.0.0.0",
    host: "omni-pgw_c.epc.mnc999.mcc999.3gppnetwork.org",
    realm: "epc.mnc999.mcc999.3gppnetwork.org",
    peer_list: [
      %{
        host: "pcrf-primary.example.com",
        realm: "epc.mnc999.mcc999.3gppnetwork.org",
        ip: "10.0.1.30",
        initiate_connection: true
      },
      %{
        host: "pcrf-backup.example.com",
        realm: "epc.mnc999.mcc999.3gppnetwork.org",
        ip: "10.0.2.30",
        initiate_connection: true
      }
    ]
  }

Load Balancing:

• Diameter protocol handles peer selection
• Requests distributed based on availability
• Automatic failover on peer failure

Hostname Resolution

Diameter Identities must be FQDNs (Fully Qualified Domain Names):

# CORRECT - FQDN format
host: "pgw_c.epc.mnc999.mcc999.3gppnetwork.org"

# INCORRECT - Not a valid Diameter Identity
host: "pgw_c"
host: "10.0.0.20"  # IP addresses not allowed

Realm Format:

• Must be valid domain name
• Typically matches 3GPP PLMN format: epc.mncXXX.mccYYY.3gppnetwork.org

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Message Flows

Successful Session Establishment

Note: QoS parameters from PCRF are translated into QERs (QoS Enforcement Rules) and programmed into PGW-U via PFCP. See PFCP Interface for QER details.

Policy Update (Network-Initiated)

Session Termination

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Error Handling

Result Codes

PGW-C handles various Diameter result codes in CCA messages:

Success Codes:

Code	Name	Action
2001	DIAMETER_SUCCESS	Continue session establishment

Permanent Failures (5xxx):

Code	Name	PGW-C Action
5002	DIAMETER_UNKNOWN_SESSION_ID	Log error, fail session
5030	DIAMETER_USER_UNKNOWN	Reject session (User Unknown)
5140	DIAMETER_ERROR_INITIAL_PARAMETERS	Log error, retry or fail
5003	DIAMETER_AUTHORIZATION_REJECTED	Reject session (Not Authorized)

Transient Failures (4xxx):

Code	Name	PGW-C Action
4001	DIAMETER_AUTHENTICATION_REJECTED	Retry or fail session
4010	DIAMETER_TOO_BUSY	Retry with backoff
4012	DIAMETER_UNABLE_TO_COMPLY	Log error, may retry

Experimental Result Codes

Vendor-specific error codes:

Experimental-Result (Grouped)
├── Vendor-Id: 10415 (3GPP)
└── Experimental-Result-Code: <vendor-specific code>

Common 3GPP Experimental Codes:

Code	Name	Meaning
5065	IP_CAN_SESSION_NOT_AVAILABLE	PCRF cannot establish session
5143	INVALID_SERVICE_INFORMATION	Service data invalid

Timeout Handling

CCR-I Timeout:

If PCRF doesn't respond to CCR-Initial within timeout:

1. PGW-C waits for configured timeout (e.g., 5 seconds)
2. If no CCA received:
   - Log: "CCR-Initial timeout for Session-ID: ..."
   - Respond to SGW-C with error cause
   - Clean up allocated resources
3. SGW-C receives: Create Session Response (Cause: Remote Peer Not Responding)

Error Response to SGW-C:

When CCR-Initial times out, the PGW-C sends a Create Session Response with cause code :remote_peer_not_responding to the SGW-C.

Failure Scenarios

Scenario 1: PCRF Rejects Session (User Unknown)

Scenario 2: PCRF Temporarily Unavailable

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Troubleshooting

Common Issues

1. Diameter Peer Connection Fails

Symptoms:

• Log: "Diameter peer not connected"
• No CCR-Initial sent

Possible Causes:

• PCRF not reachable
• Incorrect PCRF IP in configuration
• Firewall blocking Diameter port (3868)
• Incorrect Diameter identities (host/realm)

Resolution:

# Test network connectivity
ping <pcrf_ip>

# Test Diameter port (TCP 3868)
telnet <pcrf_ip> 3868

# Check Diameter identity configuration
# Ensure host and realm are FQDNs, not IPs

Verify Configuration:

config :pgw_c,
  diameter: %{
    # Must be FQDN, not IP
    host: "pgw_c.epc.mnc999.mcc999.3gppnetwork.org",
    realm: "epc.mnc999.mcc999.3gppnetwork.org",
    peer_list: [
      %{
        host: "pcrf.epc.mnc999.mcc999.3gppnetwork.org",
        ip: "10.0.0.30"
      }
    ]
  }

2. CCR-Initial Timeouts

Symptoms:

• Create Session Request fails
• Log: "CCR-Initial timeout"

Possible Causes:

• PCRF overloaded
• Network latency
• PCRF not responding to this Session-ID

Resolution:

1. Check PCRF logs for errors
2. Verify PCRF is processing requests
3. Check network latency: ping <pcrf_ip>
4. Increase timeout if network latency is high

3. Sessions Rejected by PCRF

Symptoms:

• CCA-Initial with Result-Code != 2001
• Create Session Response fails

Common Result Codes:

Result Code	Likely Cause	Resolution
5030	IMSI not in subscriber database	Provision subscriber in HSS/SPR
5003	Authorization rejected	Check subscriber permissions
4010	PCRF too busy	Retry or add PCRF capacity

Check Logs:

# PGW-C logs show:
[error] Diameter Gx error: Result-Code 5030 (DIAMETER_USER_UNKNOWN)
[error] IMSI 310260999999999 rejected by PCRF

4. QoS Not Applied

Symptoms:

• Session established but wrong QoS
• Bitrates don't match expected values

Debugging Steps:

1. Check CCA-Initial:

   • Verify QoS-Information AVP present
   • Check APN-Aggregate-Max-Bitrate-UL/DL values

2. Check PFCP Session Establishment:

   • Verify QER created with correct MBR values
   • Check PGW-U logs for QER installation

3. Verify PCRF Policy:

   • Check PCRF configuration
   • Verify subscriber profile includes correct QoS

5. Diameter Routing Issues

Symptoms:

• Diameter messages not reaching PCRF
• Log: "No route to Destination-Realm"

Cause:

• Realm mismatch between configuration and messages

Resolution:

Ensure consistency:

# All must match
config :pgw_c,
  diameter: %{
    realm: "epc.mnc999.mcc999.3gppnetwork.org",  # PGW-C's realm
    peer_list: [
      %{
        realm: "epc.mnc999.mcc999.3gppnetwork.org"  # PCRF's realm (usually same)
      }
    ]
  }

In CCR-Initial:

Origin-Realm: "epc.mnc999.mcc999.3gppnetwork.org"
Destination-Realm: "epc.mnc999.mcc999.3gppnetwork.org"

Monitoring Gx Health

Key Metrics:

# Gx message rates
rate(gx_inbound_messages_total{message_type="gx_CCA"}[5m])
rate(gx_outbound_messages_total{message_type="gx_CCR"}[5m])

# Gx error rates
rate(gx_inbound_errors_total[5m])

# Gx response success rate (new metric)
sum(rate(gx_outbound_responses_total{result_code_class="2xxx"}[5m])) /
sum(rate(gx_outbound_responses_total[5m])) * 100

# Gx response failures by PCRF host
rate(gx_outbound_responses_total{result_code_class!="2xxx"}[5m]) by (diameter_host)

# Gx session count
session_id_registry_count

# Gx message handling duration
histogram_quantile(0.95, rate(gx_inbound_handling_duration_bucket[5m]))

Response Metrics by Result Code Class:

The gx_outbound_responses_total metric provides detailed visibility into Diameter responses sent to PCRF peers, categorized by:

• message_type: Response message type (gx_RAA, gx_CCA)
• result_code_class: Result code category (2xxx, 3xxx, 4xxx, 5xxx)
• diameter_host: PCRF peer receiving the response

Common Result Codes:

• 2001 (DIAMETER_SUCCESS) - Successful response
• 3001 (DIAMETER_COMMAND_UNSUPPORTED) - Protocol error
• 5012 (DIAMETER_UNABLE_TO_COMPLY) - Cannot execute request
• 5030 (DIAMETER_USER_UNKNOWN) - Subscriber not found

Alert Examples:

# Alert on high Gx error rate
- alert: GxErrorRateHigh
  expr: rate(gx_inbound_errors_total[5m]) > 0.1
  for: 5m
  annotations:
    summary: "High Gx error rate detected"

# Alert on high Gx response failure rate
- alert: GxResponseFailureRate
  expr: |
    sum(rate(gx_outbound_responses_total{result_code_class!="2xxx"}[5m])) /
    sum(rate(gx_outbound_responses_total[5m])) > 0.1
  for: 5m
  annotations:
    summary: "High Gx response failure rate"
    description: "More than 10% of Gx responses are failures"

# Alert on PCRF-specific failures
- alert: GxPCRFFailures
  expr: rate(gx_outbound_responses_total{result_code_class=~"4xxx|5xxx"}[5m]) by (diameter_host) > 0.05
  for: 3m
  annotations:
    summary: "PCRF {{ $labels.diameter_host }} receiving failure responses"
    description: "High failure rate for PCRF host"

# Alert on session rejection
- alert: GxSessionRejection
  expr: rate(gx_inbound_errors_total{result_code="5030"}[5m]) > 0.01
  for: 5m
  annotations:
    summary: "PCRF rejecting sessions (USER_UNKNOWN)"

Debug Logging

Enable verbose Diameter logging:

# config/runtime.exs
config :logger, level: :debug

# Or at runtime
iex> Logger.configure(level: :debug)

Look for:

• [debug] Sending CCR-Initial for Session-ID: ...
• [debug] Received CCA-Initial: Result-Code 2001
• [error] Diameter error: ...

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Web UI - Diameter Peer Monitoring

OmniPGW includes a real-time Web UI for monitoring Diameter peer connections and status.

Diameter Peers Page

Access: http://<omnipgw-ip>:<web-port>/diameter

Purpose: Monitor Diameter Gx peer connectivity to PCRF in real-time

Features:

1. Peer Connection Overview

• Connected Count - Number of PCRF peers with active connection
• Disconnected Count - Number of configured but not connected peers
• Auto-refreshes every 1 second (fastest refresh of all pages)

2. Per-Peer Status Information For each configured PCRF peer:

• Host - Diameter identity (Origin-Host)
• IP Address - PCRF IP
• Port - Diameter port (default 3868)
• Status - Connected (green) / Disconnected (red)
• Transport - TCP or SCTP
• Connection Initiation - Who initiates (PGW or PCRF)
• Realm - Diameter realm
• Product Name - PCRF product identifier (if advertised)
• Application IDs - Supported Diameter applications (e.g., Gx = 16777238)

3. Expandable Details Click any peer row to see:

• Complete peer configuration
• Capabilities Exchange (CER/CEA) details
• Supported features
• Full connection state

Operational Use Cases

Monitor PCRF Connectivity:

1. Open Diameter page in browser
2. Verify all PCRF peers show "Connected"
3. Check Connection Initiation matches configuration
4. Verify Application IDs include Gx (16777238)

Troubleshoot Session Creation Failures (Gx Issues):

1. User sessions failing with "PCRF timeout" errors
2. Open Diameter page
3. Check peer status:
   - Disconnected?
     → Check network connectivity
     → Verify PCRF is running
     → Check firewall rules for TCP 3868
   - Connected but sessions failing?
     → Issue is at application level (check logs)
     → PCRF may be rejecting subscribers

Verify Diameter Configuration:

1. After configuring new PCRF peer
2. Open Diameter page
3. Verify peer appears in list
4. Check status changes to "Connected"
5. Expand peer to verify:
   - Realm matches configuration
   - Application IDs include Gx
   - Product Name shows PCRF identifier

Monitor Failover:

Scenario: Primary PCRF fails
1. Diameter page shows primary "Disconnected"
2. Verify backup PCRF still "Connected"
3. New sessions automatically use backup
4. When primary recovers, status returns to "Connected"

Detect Diameter Routing Issues:

• Peer shows "Connected" but wrong realm
• Application IDs don't include Gx (16777238)
• Product Name doesn't match expected PCRF

Identify Configuration Mismatches:

Web UI shows:
  Connection Initiation: "Peer initiates"
But configuration says:
  initiate_connection: true

This indicates:
  - OmniPGW attempts to connect
  - But PCRF also initiating
  - May cause connection race conditions

Advantages:

• Fastest refresh rate - 1 second updates
• Visual connection status - Immediate red/green indication
• No Diameter tools needed - No need for diameter CLI tools
• Peer configuration visible - Verify settings without checking config files
• Application-level details - See supported Diameter applications
• Realm verification - Confirm Diameter routing configuration

Integration with Metrics

While the Web UI provides real-time status, combine with Prometheus for:

• Historical Gx error rates
• CCR/CCA message counts
• Latency trends

Web UI = "Is it working right now?" Metrics = "How has it been working over time?"

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Related Documentation

Configuration and Policy

• Configuration Guide - Diameter configuration, PCRF peer setup
• PFCP Interface - QoS enforcement via QERs from PCC rules
• Session Management - Session lifecycle with policy integration
• QoS & Bearer Management - Detailed QoS configuration and bearer setup

Charging Integration

• Diameter Gy Interface - Online charging triggered by PCC rules
• Data CDR Format - Offline charging records with policy info
• PCO Configuration - P-CSCF delivery for IMS policy control

Operations

• Monitoring Guide - Gx metrics, policy tracking, PCRF connectivity alerts
• S5/S8 Interface - Bearer management integration with policy

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