Diameter Routing Profile

Owned by Kevin Wu
Last updated: Jan 03, 2024
10 min read

The Diameter Routing profile enables you to define the Peer Table and the Realm Routing Table properties for the Diameter Stack agent. You can also enable throttling, which allows you to prevent more than the specified number of UDRs per second to be forwarded. The throttling functionality uses the token bucket algorithm.

The Diameter Routing profile is loaded when you start a workflow that depends on it. Changes to the profile become effective when you restart the workflow. It is also possible to make changes effectively while a workflow is running. For more information about this, see the section below, To Dynamically Update the Diameter Routing Profile.

To define a Diameter Routing profile, click on the New Configuration button and then select Diameter Routing profile in the menu.

Routing Tab


The Diameter Routing profile configuration - Routing tab

Peer Table

A Diameter Stack agent that uses the Diameter Routing profile maintains transport connections with all the hosts that are defined in the Peer table list. Connections and handshakes of hosts that are not in this list are rejected with the appropriate protocol errors. Note that the system will actively try to establish connections to any hosts that are included in this list, unless the  Do Not Create Outgoing Connections option is checked in the Diameter Stack agent.

Item

Description

Item

Description

Hostname

The hostname (case sensitive) or IP address of a Diameter Identity.

For example, ggsn01.vendor.com

Note!

The content of the Origin-Host AVP in the answer commands from the specified peer should be identical to this value. If the values do not match, the MIM values published by the Diameter Stack agent that contain counters are not updated correctly. This may occur, for instance, if you have specified a hostname in this text box but the Origin-Host AVP contains an IP address. It is recommended that you consistently use either IP addresses or hostnames when configuring the Diameter profiles and agents.

Port

The port to connect to when initiating transport connections with a peer.

For example, 3868.

Protocol

The transport protocol to use when initiating a peer connection. The following settings are available:

  • TCP

  • TCP/TLS

  • SCTP

When TCP/TLS is selected, the Diameter Stack requires a secure connection from this host. You configure this feature by setting the Keystore Path and the Keystore Password in the Diameter Stack agent. For further information, see the section, Advanced Tab, in Diameter Stack Agent Configuration.

Note!

SCTP must be installed on every EC host that uses the SCTP protocol. For installation instructions, see your operating system documentation.

Throughput Threshold

If throttling has been enabled for the peer, this field will show the configured threshold for when transmissions of request UDRs should be throttled. Throttled UDRs will be routed back into the workflow.

For example 1.000 (which means a maximum of 1.000 UDRs/second will be transmitted). 

Note!

Throttling will determine if and how the workflow will limit the number of requests and UDRs sent out from the workflow. For information regarding how to configure the Diameter agent to reject incoming requests or UDRs to the workflow, see the section, Diameter Too Busy in Diameter Stack Agent Configuration . 

On Connection from Unknown Peer

When unknown peers try to connect to the Diameter Stack, you can configure how such connection attempts are to be handled. You can choose from three options from the drop box:

  • Reject - Select this option to reject all connection attempts from unknown peers. This is the default option.

  • Accept Secure Connection - Select this option to accept connection attempts from unknown peers with TLS authentication.

  • Accept All - Select this option to accept all connection attempts from unknown peers.



To Add a Host

  1. In the Diameter Routing Profile , click on the Add button beneath the Peer Table .

    The Add Host dialog opens.

    The Diameter Routing Profile - Adding a Host

  2. Enter the host name and port for the host in the Hostname and Port fields.

  3. Select protocol in the Protocol drop-down-list.

  4. If you want to enable throttling for the peer, select the Enable Throttling check box, and then enter the maximum number of request UDRs per second you want the Diameter Stack agent to transmit to the peer in the Throughput Threshold (UDR/s) field.



  5. Click on the Add button and the host will be added in the Peer Table , and then click on the Close button to close the dialog when you are finished adding hosts. 

Realm Routing Table

Realm-based routing is performed when the Destination-Host AVP is not set in a Diameter message. All realm-based routing is performed based on lookups in the Realm Routing Table.

When the lookup matches more than one set of keys, the first result from the lookup will be used for routing. For this reason, the order of the rows in the Realm Routing Table must be considered. You can control the order of the rows by using the arrow buttons. Clicking on the table columns to change the displayed sort order does not have any effect on the actual order of the rows in the Realm Routing Table.

Item

Description

Item

Description

Realm Routing Strategy

Diameter requests are routed to peers in the realms in accordance with the selected Realm Routing Strategy. The following settings are available:

  • Failover: For each realm, Diameter requests are routed to the first specified peer (primary) in the Hostnames cell, or the first host resolved by a DNS query. If the connection to the first peer fails, requests to this realm are routed to the next peer (secondary) in the cell, or the next host resolved by a DNS query. Failback to the first peer (primary) is performed when possible.

  • Round Robin: Diameter requests are evenly distributed to all the specified peers in the Hostnames cell, or peers resolved by DNS queries. If the connection to a peer fails, the requests are distributed to the remaining hosts. This also applies when UDRs are throttled due to the settings in the Peer Table.

The table below contains examples of how Diameter requests are routed to the peers of a realm, with the Round Robin strategy, depending on the peer connection state:

Diameter request are not routed to peers that are specified in the ExcludePeers field of a RequestCycle UDR. For more information about the RequestCycle UDR, see the section, RequestCycleUDR in The Diameter Base Protocol.

Enable Dynamic Peer Discovery

Select this check box when you want to use DNS queries (dynamic peer discovery) to find peer hosts in realms. The queried peer host information is buffered by the Diameter Stack agent according to the TTL (time to live) parameter in the DNS records. When the TTL has expired, the agent will attempt to refresh the information. If the refresh fails, the buffered information will be deleted.

When Enable Dynamic Peer Discovery is selected, DNS queries are performed at:

  • Workflow start

  • After TTL Expiration

  • Dynamic update of Diameter routing profile

For information about how to select DNS servers, see the section below, DNS tab.

Realm

The realm name (case sensitive). Realm is used as the primary key in the routing table lookup. If left empty, all the destination realms are valid for this route.

For example, address.com

Applications

The applications that this route serves. This entry is used as a secondary key field in the routing table lookup. If left empty all the applications are valid for this route.

For example, 3,4.

Hostnames

A list of all the peer hosts in the realm. The hostnames must be selected from the Peer Table.

When Node Discovery is set to Dynamic, you should leave this field empty.

Node Discovery

The method of finding the peer hosts in the realm:

Static - The peer hosts are specified in the Hostnames field of the Realm Routing Table.

Dynamic - The Diameter Stack agent uses DNS queries (dynamic peer discovery) to find the peer hosts. These queries may resolve to multiple IP addresses or hostnames. In order to use this setting, you may need to add DNS servers to the network interfaces of your system.

When a DNS server resolves a realm to peer hosts, it may return fully-qualified DNS domain names with a dot at the end. These trailing dots are removed by the Diameter Stack agent.

To Add a Realm

  1. In the Diameter Routing Profile, click on the Add button beneath the Realm Routing Table.
    The Add Route dialog opens.


     
    The Diameter Routing Profile - Adding a Realm
     

  2. Enter the realm name in the Realm text box.
     

  3. If the realm serves specific applications, click on the Add button beneath the Applications list box and specify the Application Id. Repeat this step for each application.
     

  4. You should only perform this step if Peer Discovery is set to Static and the peer hosts are to be specified in the Realm Routing Table. Click on the Add button beneath the Hostname list box and select a host from the drop-down list. Repeat this step for each host in the realm.
     

  5. If you specified the peer hosts of the realm in the previous step, select Static from Peer Discovery. If you want to use dynamic peer discovery instead, select Dynamic from this drop-down list.
     

  6. Click on the Add button and the realm will be added to the Realm Routing Table, and then click on the Close button to close the dialog when you are finished adding realms.

DNS Tab

The Diameter Routing profile - DNS tab

You can use the DNS tab to configure the DNS settings used for looking up peer hosts of realms.

For information about how to configure your DNS for dynamic peer discovery, see the Diameter Base Protocol (RFC 6733).

Retry Interval Time (ms)

Enter the time (in milliseconds) that the Diameter Stack agent must wait before retrying a failed DNS connection.

Max Number Of Retries

Enter the maximum number of times that the Diameter Stack agent should retry to connect to the servers in the DNS Servers list before it gives up. When the agent has attempted to connect to all servers (after an initial failed attempt), it counts as a retry.

DNS Servers

Enter the hostname or IP address of the DNS servers that can be queried. The topmost available server will be used.

If the DNS Servers list is empty, the Diameter Stack agent will use the file /etc/resolv.conf on the Execution Context host to select the DNS server. For information about how to configure resolv.conf, see your operating system documentation.

To Dynamically Update the Diameter Routing Profile

You can refresh the routing table of a Diameter Stack agent while a workflow is running. When the agent refreshes the routing table, it reads the updated Peer Table, Realm Routing Table and Realm Routing Strategy from the selected Diameter Routing Profile.
The setting Enable Dynamic Peer Discovery in the Routing tab and the settings in the DNS tab is not read from the Diameter Routing table at refresh. To make changes to these settings effective, you must restart the workflow(s).

The routing table can be refreshed from the Workflow Monitor or from the Command Line Tool. In the Workflow Monitor, double-click the Diameter Stack agent to open the Workflow Status Agent configuration. In the Command tab, select the Update Routing Table button to refresh the routing table.

Command Line Tool

 Run the following command:

mzsh mzadmin/<password> wfcommand <workflow name> <Diameter Stack agent name>


When Round Robin is the selected Realm Routing Strategy, you can reset the selection cycle by running the following command:

mzsh mzadmin/<password> wfcommand <workflow name> <Diameter Stack agent name> clearstrategystate

To Read the Realm Routing Table in APL

You can use the Diameter Stack MIM value Realm Routing Table to read the realm routing table of a Diameter Stack Agent from APL. The MIM value is of the map<string,map<string, list<string>>> type and is defined as a global MIM context type. The string values in the outer map contain the realm names (primary key). The string values of the inner map contain the applications (secondary key). The lists in the map contain the hostnames of the peers in the realm.

The string values in the outer map contain the realm names (primary key). The string values of the inner map contain the applications (secondary key). The lists in the map contain the hostnames of the peers in the realm.

Asterisks (*) are used in the strings to denote unspecified realm name or unspecified applications. The values in the inner and outer maps are sorted exactly as the Realm Routing Table of the selected Diameter routing profile.

Realm

Applications

Peers

dr



peer1, peer2



100,200

peer3, peer4





peer5, peer6

For more information about MIM values published by the Diameter Stack agent, see Diameter Stack Agent Input/Output Data and MIM.