The aim of this guide is to demonstrate the provider solution for designing an access network section using XGS-PON technology with Eltex equipment and to demonstrate the practices of using this equipment.

Intended audience

This guide will be useful for data network engineers of telecom providers' networks at the stage of network section design, when determining the last mile technology to be used at the network section. This guide is also recommended when considering modernization of an access network section that is built using PON technology, when planning a transition to XGS-PON or implementing new connection diagrams for an already built access network using XGS-PON equipment.

Proposed network diagram

The proposed solution examines multiple typical connection diagrams using ONTs operating in bridge mode.

Advantages of the solution

The distinctive feature of this connection diagram is transparent transmission of the data of various services offered in different VLANs via the ONT. This approach to configuration allows you to connect various equipment, from access switches to home routers, to the LAN-interfaces of the ONT. Thus, an ONT configured in bridge mode can be connected to both the equipment in the operator's area of responsibility and any home subscriber router.

ONT configuration in such diagrams is relatively simple and is carried out entirely by means of OLT. Management and monitoring can be performed using the Eltex EMS management system, for which a separate physical or virtual server is used.

Since Eltex XGS-PON OLTs support operating PON ports in GPON mode, as well as simultaneous GPON and XGS-PON operation (for OLT of LTX-C series), it is possible to adjust this switching scheme to be able to connect ONTs using GPON technology. Examples of such diagrams are given in the appendices:

• Appendix 1. XGS-PON+GPON on OLT LTX-8/16C combo (XGS-PON diagram)
• Appendix 2. XGS-PON+GPON on OLT LTX-8/16 (XGS-PON diagram)

Possible product solutions

Possible options of equipment to use for the given diagram:

Aggregation switch

MES series aggregation switches by Eltex supporting 40/100G interfaces are recommended for connecting the PON access segment to the upstream network.

XGS-PON OLT

The following OLT models can be used as XGS-PON exchange terminals.

XGS-PON ONT

The following ONT models can be used as XGS-PON subscriber terminals.

An optimal solution for connecting access switch to PON disribution network can be NTX-SFP-100 — an XGS-PON ONT in an SFP module form factor, that connects to the switch and is powered by it. OLT exchange equipment will identify this SPF-ONT as an ordinary ONT. On the access switch side, the same SFP-ONT will be identified as a regular ethernet SFP module. Another option is to use NTX-1F with the ability to connect Ethernet SFP module to the LAN interface to organize an optical connection to the downstream access switch.

Router

The following devices can be used as a home router.

In the given diagram, RG-5520G-Wax by Eltex is used as a home router. The device supports 802.11ax standard that works with two streams simultaneously to deliver speed up to 1.2 Gbps on a 5 GHz band. The WAN interface on these devices is capable of 2.5G operation.

Access switch

It is recommended to use MES series access switches by Eltex to connect a PON segment to a downstream access segment.

EMS server

System requiements for the server hardware where EMS will be installed vary depending on the planned number of OLTs and ONTs to be connected. Recommended OS: Ubuntu 20.04, Ubuntu 22.04.