IP Access for network management

Overview

For network management purposes, the Alcatel-Lucent 1850 TSS-5 supports the following types of IP Access:

When operating as a SONET/SDH network element with a SYSCTL and VLNC50/52/55 installed, Alcatel-Lucent 1850 TSS-5 can serve as a TL1 Translation Device (T-TD) by acting as a gateway network element that allows WaveStar^® CIT to communicate to other network elements (NEs) through an IP access network. This capability allows you to send TL1 commands from WaveStar^® CIT located on a TCP/IP based network to various NEs connected on an OSI network.
As a SONET/SDH VLNC50/52/55 network element, Alcatel-Lucent 1850 TSS-5 can functionally encapsulate IP packets within OSI packets to be transmitted through the OSI network to the proper NE. Thus Alcatel-Lucent 1850 TSS-5 supports IP based protocols such as FTP by providing end-to-end IP connectivity between OS and NE. This capability is called IP tunneling. IP tunneling is required to support remote database backup/restore in between Alcatel-Lucent 1850 TSS-5 systems.
With SYSCTL and VLNC50/52/55 circuit packs installed, Alcatel-Lucent 1850 TSS-5 can also serve as a File Transfer Translation Device (FTTD) by acting as an FTAM-FTP gateway network element. The FTAM-FTP gateway network element translates FTAM over OSI presentation to FTP over TCP/IP. The FTAM-FTP gateway supports software downloads, database backups, and database restores.
Alcatel-Lucent 1850 TSS-5 supports Simple Network Management Protocol (SNMP) for data network applications supported by the VLNC40/VLNC42/VLNC42B/VLNC60/VLNC61/VLNC62/VLNC64 circuit pack. Alcatel-Lucent 1850 TSS-5 provides limited support for certain reports and traps (alarms and events autonomous messages).
Alcatel-Lucent 1850 TSS-5 also supports Network Time Protocol (NTP) using IP tunneling to synchronize the time and date to a standard time reference.

TL1 GNE (T-TD)

When operating as a SONET/SDH VLNC50/52/55 network element, Alcatel-Lucent 1850 TSS-5 can copy the application information within an IP packet into an OSI packet. This translation is performed at the application layer. When acting as a TL1 translation device, Alcatel-Lucent 1850 TSS-5 system must be provisioned with a list of possible OSs. If an OS is not on the list residing within the system, a connection from that OS will not be accepted. When Alcatel-Lucent 1850 TSS-5 is used as a TL1 translation device it is referred to as the T-TD GNE (Gateway Network Element).

Figure 5-13: TL1 translation device

OSI associations and TCP/IP connections

When used as a GNE, Alcatel-Lucent 1850 TSS-5 supports a total of 105 OSI associations (logins). Each TCP/IP (or Telnet) connection can support 64 associations. If the user attempts to establish a sixty-fifth association from a TCP/IP connection, the connection is denied. The user must establish an additional TCP/IP (or Telnet) session. The Alcatel-Lucent 1850 TSS-5 GNE supports up to 20 TCP/IP connections. The combined number of OSI associations on all TCP/IP sessions cannot exceed 105.

IP tunneling

The Alcatel-Lucent IP tunneling solution consists in encapsulating IP packets inside CLNP (ISO 8473 ConnectionLess Network Protocol) PDU, in order to be able to use an existing OSI-based embedded Data Communications Network (DCN) for IP traffic.

With the IP tunneling over CLNP solution, Alcatel-Lucent 1850 TSS-5 NE can support the following two customer applications: IP access and IP fringe.

An IP access application is shown in Figure 5-14, IP tunneling, where an IP based OS (for example, SNMP manager) located in the IP access DCN manages a remote Alcatel-Lucent 1850 TSS-5 NE located in the OSI-based embedded DCN. The IP application initiated at the OS terminates at the remote NE.

Figure 5-14: IP tunneling

An IP fringe application, where an IP based OS located in the IP access DCN manages an IP managed NE (non Alcatel-Lucent 1850 TSS-5) on the fringe of Alcatel-Lucent 1850 TSS-5 OSI-based embedded DCN. The IP application initiated at the OS terminates at the IP managed NE. Note that if the IP managed NE is not directly connected to Alcatel-Lucent 1850 TSS-5 remote NE via the LAN, but can be reached via additional routers, some static routes have to be provisioned manually on the routers.

Alcatel-Lucent 1850 TSS-5 and Alcatel-Lucent 1850 Transport Service Switch 100/Alcatel-Lucent 1850 Transport Service Switch 320 IP tunneling interworking

In a typical network, the Alcatel-Lucent 1850 TSS-5 is a remote NE (RNE) interworking with an Alcatel-Lucent 1850 Transport Service Switch 100 or Alcatel-Lucent 1850 Transport Service Switch 320 functioning as the gateway NE (GNE). The Alcatel-Lucent 1850 Transport Service Switch 100/Alcatel-Lucent 1850 Transport Service Switch 320 GNE supports T-TD (TL1 Translation Device) to translate TL1 over TCP/IP to TL1 over OSI. This allows TL1 management of a remote Alcatel-Lucent 1850 TSS-5.

However, to fully support IP tunneling interworking between a remote Alcatel-Lucent 1850 TSS-5 and the Alcatel-Lucent 1850 Transport Service Switch 100/Alcatel-Lucent 1850 Transport Service Switch 320 GNE, Alcatel-Lucent 1850 TSS-5 supports a provisionable NSAP selector and a reduced Maximum Transmission Unit (MTU) size.

To support interworking with the Alcatel-Lucent 1850 Transport Service Switch 100/Alcatel-Lucent 1850 Transport Service Switch 320, the NSAP selector parameter must be provisioned to f0 (04 default value) at the remote Alcatel-Lucent 1850 TSS-5. This allows software operations (download/backup/restore) to a remote Alcatel-Lucent 1850 TSS-5 using FT-TD (File Transfer Translation Device) to translate FTP over TCP/IP to FTAM over OSI.

Encapsulating IP packets

When functioning as a GNE, Alcatel-Lucent 1850 TSS-5 acts as the tunnel entrance, i.e., the interface between IP and CLNP. When an IP packet is received from the LAN interface of the GNE, if it is not destined for the GNE, the received IP packet is encapsulated into CLNP PDU(s) as simple CLNP user data, loosing any IP protocol meanings (such as IP addressing and life time), as shown in the following figure.

Figure 5-15: Encapsulated IP packets

For the CLNP PDU that contains the encapsulated IP packet, the CLNP source address is the NSAP of the NE where the IP packet is encapsulated (tunnel entrance), and the CLNP destination address is the NSAP of the NE where the IP packet will be de-capsulated (tunnel exit). The CLNP PDU then is routed via the ISO-10589 "IS to IS intra-domain information exchange protocol (IS-IS)" within the embedded OSI DCN. Therefore, the IP tunneling over CLNP is transparent for the IP world. The CLNP world is only used to carry the IP traffic and there is no possible connections between the OSI applications and the IP applications. The IP tunnel serves as a normal point-to-point link for the IP traffic between two NSAP entities (the tunnel entrance and tunnel exit). Note that because the IP traffic flows in both directions between two NSAP entities, the tunnel entrance entity also serves as the tunnel exit entity, and vice versa.

In the tunnel entrance, the way to associate an IP destination address in the IP packet with an OSI NSAP address (the NSAP of tunnel exit entity) can be derived by the static user provisioned information or by the automatic distributed tunnel routing information, called Tunnel Auto Provisioning (TAP).

Tunnel auto provisioning (TAP)

In the OSI networks, the network elements use the ISO-10589 "IS to IS intra-domain information exchange protocol (IS-IS)" to exchange the topology information. The knowledge by every network element of the whole network topology at a given time allows the computation of the optimal route to any possible destination on the network. The IS-IS protocol provides for the inclusion of optional variable length fields in all IS-IS packets. This allows additional IP specific information to be added to the OSI IS-IS routing packets.

The topological information between network elements (or called intermediate systems) is communicated by sending a specific IS-IS PDU called LSP (Link-State PDU). In the LSP optional fields, the NEs send (advertise) information about the IP sub-nets that can be reached via that NE. By default, this will be locally attached subnet, but other sub-nets can also be provisioned for the advertisement.

The advertising of IP information using the LSP options can be enabled or disabled via the user interfaces. Based on the specification of the IS-IS protocol, any intermediate systems that could not recognize the encoded optional fields shall just ignore and pass through these fields unchanged. This makes it possible for NEs that advertise both OSI and IP routing information work with NEs that advertise OSI routing information only.

With automatic distribution of IP routing information via IS-IS LSP, a NE, which learned such information, then can associate an IP destination address of an IP packet with an OSI NSAP address, and uses this NSAP address as the destination address of CLNP PDU(s) which encapsulates the IP packet.

FTAM-FTP gateway network element

Alcatel-Lucent 1850 TSS-5 can serve as a File Transfer Translation Device (FTTD) by acting as an FTAM-FTP gateway network element. The FTAM-FTP gateway network element translates FTAM over OSI presentation to FTP over TCP/IP. The FTAM-FTP gateway supports software downloads, database backups, and database restores.

The following figure shows an Alcatel-Lucent 1850 TSS-5 provisioned as an FTAM-FTP gateway network element. The FTAM-FTP gateway network element allows remote Alcatel-Lucent 1850 TSS-5 network elements to request software downloads and database restores from an FTP server. The FTAM-FTP gateway network element also allows remote Alcatel-Lucent 1850 TSS-5 network elements to backup databases to an FTP server.