Network protocols

General

Information exchange on the Internet is based on the TCP/IP network protocol (Transmission Control Protocol/Internet Protocol) and executed by means of direct socket connections. The TCP/IP protocol is a fault-tolerant protocol that detects and eliminates transmission errors.

The computer's IP address and a port number uniquely specify a socket. The server program generates a socket upon boot-up and waits for requests. A client computer connects to the server by generating a socket and connecting it to the socket of the server. Next, the information exchange takes place within the protocol set by the server socket. The connection is terminated when one of the partners closes the socket. This is usually the client because the server waits for further requests.

The port numbers up to 1023 are reserved for specific transmission protocols. They are called well-known ports and must only be used for the respective protocols. For example, the following fixed server port numbers (in parentheses) have been assigned on the Internet to particular transmission protocols: HTTP (80), FTP (21), telnet (23), SMTP (25), POP3 (110), and HTTPS (443). Port numbers above 1023 are called user ports.

In contrast to the default port numbers, you can choose the port number for most additional services.

A socket connection within a network must be unique. A port can only be assigned once for each network address.

Network interfaces

Usually, each server or desktop PC on which PPM can be installed has one to two network resources or cards (also called NIC = network interface card). Each NIC provides a unique address (IP) within the network at which the server can be reached. Usually, one NIC is sufficient for operating PPM. Each service provided by PPM runs on an individual IP and port combination unique for the NIC.

If multiple NICs that can be used by an application (management networks excluded) are available in the server, PPM can also be configured on individual NIC addresses (IP + port). Using multiple network cards becomes interesting if the number of available ports is limited.

PPM network protocols

Communication among the PPM components is based on TCP/IP. Other protocol families (e.g., IPX, SPX) are not supported. PPM uses the following TCP/IP protocols:

Component

Protocol

Default port

Load balancer

HTTP/HTTPS

4080/4443

CORBA registry

IIOP

17590 + n

CORBA registry

Activation port

17589

RMI registry

RMI/SSL RMI/zipped RMI

17500

<client name>_cs

RMI/SSL RMI/zipped RMI

17501 + 2*n

<client name>_as

RMI/SSL RMI/zipped RMI

17502 + 2*n

PPM Web

HTTP

17101

PPM Web

AJP

17201

Elasticsearch

HTTP

17047

ZooKeeper

HTTP

17050

UMC

HTTP

17100

UMC

AJP

17200

Cloud Agent

HTTP/HTTPS

17004

RMI (Remote Method Invocation)

PPM client server and PPM front-end use this protocol to exchange data. PPM uses the protocol variant JRMP (Java RMI Message Protocol) as the transfer standard. The PPM front-end usually requires two RMI communication channels (socket connections): one for the cross-system RMI registry server and the other for the PPM client server, i.e., the PPM server itself. By default, the RMI protocol requires a direct socket connection.

Under certain circumstances, you can configure the PPM system so that only a single RMI communication channel is needed (see chapter Data transfer using HTTPS tunneling).

Corba (Common Object Request Broker Architecture)

The Performance Dashboard Web application, the Management views, and the query API use this protocol to communicate with the PPM client server within a server installation.

JDBC (Java DataBase Connectivity)

Java applications use this standardized protocol to access an RDBMS. The JDBC drivers required for this are not part of the PPM installation and are provided by the database manufacturer.

HTTP (Hyper Text Transfer Protocol)

PPM uses this protocol only to transfer the HTML document pages, text-based configuration files (*.properties), and Java archive files required to run the PPM user interface in the browser.

The Web application server also uses this protocol to publish Management views and to run Performance Dashboard.

Instead of the HTTP protocol, you can also use the secure variant, HTTPS.