Juniper MX Line Card Comparison Guide: MPC vs MIC, Generations & Compatibility
Understanding Juniper MX Line Cards: MPCs, MICs & Compatibility
The Juniper MX Series is built around a flexible, modular architecture. Instead of replacing an entire chassis every time your network requirements change, you can scale performance and add new interfaces by using MPC (Modular Port Concentrator) and MIC (Modular Interface Card) line cards.
This guide breaks down the differences between MPCs and MICs, explains each generation, and provides practical compatibility information for MX240, MX480, and MX960 routers.
Already comparing MPC generations? See our focused guide: Juniper MPC4 vs MPC5 vs MPC7 Comparison.
MX Architecture Basics: Chassis, Slots, MPCs and MICs
A Juniper MX chassis consists of:
- Chassis (MX240, MX480, MX960)
- Routing Engines (REs)
- Switch Fabric / SCBs
- MPCs (line cards that perform forwarding and, on modular generations, host MICs)
- MICs (interface modules that provide the actual ports on modular MPCs)
The MPC provides the processing, the MIC provides the ports (on modular MPCs), and the chassis provides the backplane and fabric bandwidth.
What Is an MPC?
MPCs (Modular Port Concentrators) are the primary forwarding and service cards in MX Series routers. They provide:
- Packet forwarding and queuing
- Support for firewall filters, CoS and QoS
- Advanced services (NAT, VPN, EVPN/VXLAN)
- On modular generations (MPC1/2/3/6/8/9), slots for MICs
Later generations such as MPC5E, MPC7E and MPC10E are fixed-configuration line cards — all ports are built into the card, and they do not accept MICs.
Each MPC generation improves scale, throughput and interface support.
What Is a MIC?
MICs (Modular Interface Cards) are pluggable interface modules that insert into modular MPCs. MICs provide:
- Physical interfaces (SFP, SFP+, QSFP+, QSFP28, depending on model)
- Different link types (1GbE, 10GbE, 40GbE, 100GbE)
- Flexible combinations of multirate connectivity
This modular approach allows you to upgrade interfaces without replacing the MPC, as long as you are using a modular MPC generation.
MPC Generations Overview
| MPC Family | MIC Slots | Typical Ports / Speeds | Advantages | Best For |
|---|---|---|---|---|
| MPC3E | Yes (modular — supports MICs) | 1GbE / 10GbE / 40GbE / 100GbE depending on MIC (MIC-3D, MIC3-Q, MIC3-100G, MIC-6Q, etc.) | Proven platform, flexible MIC options, strong value on MX240/480/960 | Budget-conscious MX expansions that still need 10G/40G/100G options |
| MPC5E | No (fixed configuration) | High-density 10GbE, 40GbE and 100GbE ports built into the card (model-dependent) | Higher throughput and feature scale than MPC3E, no MIC complexity | Service provider edge and aggregation with mixed 10G/40G/100G needs |
| MPC7E | No (fixed configuration) | Multirate 10G/40G/100G (e.g. MPC7E-10G, MPC7E-MRATE) | Major performance jump, better EVPN/VXLAN and CoS scale | Modern metro/core routing and high-bandwidth MX480/MX960 deployments |
| MPC10E | No (fixed configuration) | High-density 100GbE and multirate 10G/25G/50G/100G (e.g. MPC10E-15C-MRATE) | Next-generation NPUs, highest scale before 400G-class MPC14 | Core, peering, and data center gateway roles that need dense 100G |
MIC Types and Capabilities
The MIC families below are used with modular MPCs only (MPC1, MPC2, MPC3/3E/3E-NG, MPC6, MPC8, MPC9). Newer fixed-configuration cards like MPC5E, MPC7E and MPC10E do not have MIC slots.
| MIC Family | Supported Speeds | Typical Ports | Compatible Modular MPCs* | Best For |
|---|---|---|---|---|
| MIC-3D / MIC-3D-20GE | 1GbE / 10GbE | Up to 20× 1GbE SFP, or 2–4× 10GbE SFP+ | MPC1, MPC2, MPC3/3E (model- and Junos-dependent) | Enterprise access, ISP edge, dense 1G with some 10G uplinks |
| MIC3-Q (40G MICs) | 40GbE (with 4×10G breakout on supported QSFP+) | 2× or 4× QSFP+ | MPC2, MPC3/3E (per Juniper MIC/MPC matrix) | 40G aggregation and 10G-to-40G migration |
| MIC3-100G | 100GbE | 1× or 2× 100G ports (CFP/CFP2/QSFP28, model-dependent) | MPC3E and select MPC2 (where supported) | Cost-efficient 100G uplinks and 100G peering |
| MIC-6Q | 40GbE | 6× QSFP+ | MPC1, MPC2, MPC3/3E, MPC6, MPC8, MPC9 (chassis- and Junos-dependent) | High-density 40G leaf-spine and fabric aggregation |
| Multirate QSFP MICs | 10GbE / 40GbE / 100GbE | Mixed QSFP+/QSFP28 ports | MPC3E, MPC6, MPC8, MPC9 (where supported) | Mixed-speed environments and gradual 10G → 40G → 100G migration |
*Always confirm specific MIC/MPC/chassis compatibility against the official Juniper hardware guide and your target Junos version.
Chassis Compatibility (MX240 / MX480 / MX960)
| Chassis | MPC Slots | Compatible MPCs | Notes |
|---|---|---|---|
| MX240 | 2 Slots | MPC3E–MPC10E (plus earlier MPCs in many deployments) | Compact chassis; ideal for POPs and smaller edge sites |
| MX480 | 6 Slots | MPC3E–MPC14E | Most flexible carrier platform; common for edge and core roles |
| MX960 | 12 Slots | MPC3E–MPC14E | Highest scale and bandwidth; widely used as core and peering router |
Recommended MPC / MIC Combinations
1. High-Density 100GbE
- MPC10E (for dense 100G edge/core)
2. 40GbE Aggregation
- MPC7E fixed-configuration cards for high-performance 40G/100G
- MPC3E + MIC3-Q or MIC-6Q for cost-effective 40G with modular flexibility
3. Mixed Environments
- MPC7E-MRATE in MX480/MX960 for mixed 10G/40G/100G
- MPC10E multirate models where you need dense 100G and flexible lower-speed breakouts
4. Budget Deployments
- MPC3E + MIC-3D-20GE or MIC-6Q in MX480/MX960 for dense 1G/10G/40G at lower cost
- MPC4E where you need a step up from older MPCs but don’t require MPC7E/10E scale yet
Popular MPC & MIC Products
- Juniper MPC10E-15C-MRATE
- Juniper MPC7E-10GE
- Juniper MPC7E-MRATE
- Juniper MIC3-3D-1X100GE-CFP
- Juniper MIC3-3D-2X40GE-QSFPP
How to Choose the Right MPC or MIC
1. Throughput Needs
Newer generations (MPC7E, MPC10E) offer substantial performance gains over earlier cards.
2. Port Speeds
10GbE / 40GbE → MPC5E or MPC7E
Dense 100GbE → MPC7E or MPC10E
3. Feature Scale
Advanced CoS, firewall filters and EVPN/VXLAN scale far better on MPC7E and newer compared to earlier generations.
4. Budget
MPC3E and MPC4E remain strong values for cost-conscious MX480/MX960 expansions where absolute maximum scale is not required.
Related Resources
Conclusion
The Juniper MX platform is a highly scalable and flexible routing solution, and understanding the differences between MPC and MIC cards is key when planning network upgrades. Whether you need more 10GbE ports, 40GbE aggregation, or dense 100GbE there is an MPC/MIC combination designed to match your environment.
BrightStar Systems carries all major Juniper MPC and MIC models, fully tested and backed by our 1-Year In-House Warranty. If you have questions about compatibility, availability or selecting the right hardware, our engineering team is here to help.